Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FACE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2004

Recognition of famous faces in the medial temporal lobe: an invasive ERP study.

OBJECTIVE: To investigate the involvement of the rhinal cortex and the hippocampus in the processing of famous faces in contrast to nonfamous faces using intracranial event-related potentials (ERPs), and to analyze repetition effects for famous and nonfamous faces. METHODS: ERPs were elicited by pictures of famous and nonfamous faces and recorded from rhinal and hippocampal sites of intracranial electrodes in 10 presurgical patients with unilateral medial temporal lobe epilepsy. Famous and nonfamous faces were presented twice and mixed with distorted faces serving as targets. There was no instruction for an overt discrimination between famous and nonfamous faces. In contrast to nonfamous faces, famous faces stimulate processes related with access and retrieval of semantic memory. RESULTS: All faces evoked anterior medial temporal lobe N400-like (AMTL-N400) potentials in the rhinal cortex and P600-like potentials in the hippocampus. The AMTL-N400 and the hippocampal P600 amplitudes were larger for famous faces than for nonfamous faces. Mean amplitudes of the first and second presentation of famous faces suggest a repetition effect for the rhinal sites; however, they are significant only in the later signal components. No repetition effect was found for nonfamous faces and for potentials from the hippocampus. CONCLUSION: The anterior medial temporal lobe N400 and the hippocampal P600 may be related to the access and retrieval of person-specific semantic memory.

Adult↗
PubMed1992

[The anthropomorphic proportions of the face: an evaluation of the response to orthodontic surgical treatment of Angle class III].

The purpose of this investigation was: to examine the anthropometric facial presurgical and postsurgical indices of patients having a dento-skeletal class III malocclusion and who were treated with the orthodontic-surgical procedure. To evaluate the postsurgical response of the soft tissues, according to the type of approach: mandibular surgery or maxillo-mandibular surgery. To recognize, if it is possible, what indices are to be considered more involved in the esthetic change. Ninety pre and postoperative frontal photographs of 45 subjects were studied. The subjects were 32 females and 15 males who had a dento-skeletal class III malocclusion and who had undergone the orthodontic-surgical treatment (21 had sagittal bilateral mandibular osteotomy, 24 had sagittal bilateral mandibular osteotomy + Le Fort I). The photographs were taken with lips in repose, relaxed soft tissue and centric occlusion. The mean age of the patients was 23 years (ranging 16-35). The post-treatment follow-up went from 1 to 3 years. 11 frontal landmarks: n = nasion, sn = subnasale, sto = stomion, sl = sublabiale, gn = gnathion, go = gonion (bilateral), zy = zygoma (bilateral), ch = cheilion (bilateral) were recognized and 3 horizontal and 5 vertical measurements were taken: zygomatic width (zy-zy), mouth width (ch-ch), gonial width (go-go); face height (n-gn), lower face height (sn-gn), upper face height (n-sto), height of lower third of the face (sto-gn), medial vertical chin height (sl-gn). 11 pre and post-treatment facial indices were obtained from the ratio per cent of the measurements previously mentioned using the method of Farkas: Facial (n-gn-zy-zy), Mandible-face width (go-go/zy-zy), Upper face (n-sto/zy-zy), Mandible width-face height (go-go/n-gn), Mandibular (sto-gn/go-go), Mouth face width (ch-ch/zy-zy), Lower face-face height (sn-gn/n-gn), Mandible face height (sto-gn/n-gn), Mandible-upper face height (sto-gn/n-sto), Mandible-lower face height (sto-gn/sn-gn), Chin-face height (sl-gn/sn-gn). In each patient the mean values, with their standard deviations, were calculated according to the sex for each index. A different group of average values was calculated according to the sex and to the type of surgical approach; 17 females and 4 males underwent a mandibular setback osteotomy and 15 females and 9 males underwent a sagittal bilateral mandibular osteotomy + Le Fort I osteotomy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1999

Organization of face and object recognition in modular neural network models.

There is strong evidence that face processing in the brain is localized. The double dissociation between prosopagnosia, a face recognition deficit occurring after brain damage, and visual object agnosia, difficulty recognizing other kinds of complex objects, indicates that face and non-face object recognition may be served by partially independent neural mechanisms. In this paper, we use computational models to show how the face processing specialization apparently underlying prosopagnosia and visual object agnosia could be attributed to (1) a relatively simple competitive selection mechanism that, during development, devotes neural resources to the tasks they are best at performing, (2) the developing infant's need to perform subordinate classification (identification) of faces early on, and (3) the infant's low visual acuity at birth. Inspired by de Schonen, Mancini and Liegeois' arguments (1998) [de Schonen, S., Mancini, J., Liegeois, F. (1998). About functional cortical specialization: the development of face recognition. In: F. Simon & G. Butterworth, The development of sensory, motor, and cognitive capacities in early infancy (pp. 103-116). Hove, UK: Psychology Press] that factors like these could bias the visual system to develop a processing subsystem particularly useful for face recognition, and Jacobs and Kosslyn's experiments (1994) [Jacobs, R. A., & Kosslyn, S. M. (1994). Encoding shape and spatial relations-the role of receptive field size in coordination complementary representations. Cognitive Science, 18(3), 361-368] in the mixtures of experts (ME) modeling paradigm, we provide a preliminary computational demonstration of how this theory accounts for the double dissociation between face and object processing. We present two feed-forward computational models of visual processing. In both models, the selection mechanism is a gating network that mediates a competition between modules attempting to classify input stimuli. In Model I, when the modules are simple unbiased classifiers, the competition is sufficient to achieve enough of a specialization that damaging one module impairs the model's face recognition more than its object recognition, and damaging the other module impairs the model's object recognition more than its face recognition. However, the model is not completely satisfactory because it requires a search of parameter space. With Model II, we explore biases that lead to more consistent specialization. We bias the modules by providing one with low spatial frequency information and the other with high spatial frequency information. In this case, when the model's task is subordinate classification of faces and superordinate classification of objects, the low spatial frequency network shows an even stronger specialization for faces. No other combination of tasks and inputs shows this strong specialization. We take these results as support for the idea that something resembling a face processing "module" could arise as a natural consequence of the infant's developmental environment without being innately specified.

Journal Article↗
PubMed2000

Functional delineation of the human occipito-temporal areas related to face and scene processing. A PET study.

By measuring regional cerebral blood flow using PET, we delineated the roles of the occipito-temporal regions activated by faces and scenes. We asked right-handed normal subjects to perform three tasks using facial images as visual stimuli: in the face familiar/unfamiliar discrimination (FF) task, they discriminated the faces of their friends and associates from unfamiliar ones; in the face direction discrimination (FD) task, they discriminated the direction of each unfamiliar face; in the dot location discrimination (DL) task, they discriminated the location of a red dot on a scrambled face. The activity in each task was compared with that in the control fixation (CF) task, in which they fixated on the centre of a display without visual stimuli. The DL task activated the occipital cortices and posterior fusiform gyri bilaterally. During the FD task, the activation extended anteriorly in the right fusiform gyrus and laterally to the right inferior temporal cortex. The FF task further activated the right temporal pole. To examine whether the activation due to faces was face-specific, we used a scene familiar/unfamiliar discrimination (SF) task, in which the subjects discriminated familiar scenes from unfamiliar ones. Our results suggest that (i) the occipital cortices and posterior fusiform gyri non-selectively respond to faces, scrambled faces and scenes, and are involved mainly in the extraction of physical features of complex visual images; (ii) the right inferior temporal/fusiform gyrus responds selectively to faces but not to non-face stimuli and is involved in the visual processing related to face perception, whereas the bilateral parahippocampal gyri and parieto-occipital junctions respond selectively to scenes and are involved in processing related to scene perception; and (iii) the right temporal pole is activated during the discrimination of familiar faces and scenes from unfamiliar ones, and is probably involved in the recognition of familiar objects.

Adult↗
PubMed2005

Context influences early perceptual analysis of faces--an electrophysiological study.

Electrophysiological and hemodynamic correlates of processing isolated faces have been investigated extensively over the last decade. A question not addressed thus far is whether the visual scene, which normally surrounds a face or a facial expression, has an influence on how the face is processed. Here we investigated this issue by presenting faces in natural contexts and measuring whether the emotional content of the scene influences processing of a facial expression. Event-related potentials were recorded to faces (fearful/neutral) embedded in scene contexts (fearful/neutral) while participants performed an orientation-decision task (face upright or inverted). Two additional experiments were run, one to examine the effects of context that occur without a face and the other to evaluate the effects of faces isolated from contexts. Faces without any context showed the largest N170 amplitudes. The presence of a face in a fearful context enhances the N170 amplitude over a face in neutral contexts, an effect that is strongest for fearful faces on left occipito-temporal sites. This N170 effect, and the corresponding topographic distribution, was not found for contexts-only, indicating that the increased N170 amplitude results from the combination of face and fearful context. These findings suggest that the context in which a face appears may influence how it is encoded.

Adult↗
PubMed2001

Face recognition and emotional valence: processing without awareness by neurologically intact participants does not simulate covert recognition in prosopagnosia.

Covert face recognition in neurologically intact participants was investigated with the use of very brief stimulus presentation to prevent awareness of the stimulus. In Experiment 1, skin conductance response (SCR) to photographs of celebrity and unfamiliar faces was recorded; the faces were displayed for 220 msec and for 17 msec in a within-participants design. SCR to faces presented for 220 msec was larger and more likely to occur with familiar faces than with unfamiliar faces. Face familiarity did not affect the SCR to faces presented for 17 msec. SCR was larger for faces of good than for faces of evil celebrities presented for 17 msec, but valence did not affect SCR to faces displayed for 220 msec. In Experiment 2, associative priming was found in a face familiarity decision task when the prime face was displayed for 220 msec, but no facilitation occurred when primes were presented for 17 msec. In Experiment 3, participants were able to differentiate evil and good faces presented without awareness in a two-alternative forced-choice decision. The results provide no evidence of familiarity detection outside awareness in normal participants and suggest that, contrary to previous research, very brief presentation to neurologically intact participants is not a useful model for the types of covert recognition found in prosopagnosia. However, a response based on affective valence appears to be available from brief presentation.

Adolescent↗
PubMed2007

Abnormal activation of the social brain during face perception in autism.

ASD involves a fundamental impairment in processing social-communicative information from faces. Several recent studies have challenged earlier findings that individuals with autism spectrum disorder (ASD) have no activation of the fusiform gyrus (fusiform face area, FFA) when viewing faces. In this study, we examined activation to faces in the broader network of face-processing modules that comprise what is known as the social brain. Using 3T functional resonance imaging, we measured BOLD signal changes in 10 ASD subjects and 7 healthy controls passively viewing nonemotional faces. We replicated our original findings of significant activation of face identity-processing areas (FFA and inferior occipital gyrus, IOG) in ASD. However, in addition, we identified hypoactivation in a more widely distributed network of brain areas involved in face processing [including the right amygdala, inferior frontal cortex (IFC), superior temporal sulcus (STS), and face-related somatosensory and premotor cortex]. In ASD, we found functional correlations between a subgroup of areas in the social brain that belong to the mirror neuron system (IFC, STS) and other face-processing areas. The severity of the social symptoms measured by the Autism Diagnostic Observation Schedule was correlated with the right IFC cortical thickness and with functional activation in that area. When viewing faces, adults with ASD show atypical patterns of activation in regions forming the broader face-processing network and social brain, outside the core FFA and IOG regions. These patterns suggest that areas belonging to the mirror neuron system are involved in the face-processing disturbances in ASD.

Adult↗
PubMed1985

Role of low and high spatial frequencies in the face-selective responses of neurons in the cortex in the superior temporal sulcus in the monkey.

There are neurons in the cortex in the anterior part of the superior temporal sulcus of the macaque monkey with visual responses selective for faces. One aim of the present study was to analyze further the information which leads them to respond, by measuring their responses to parametrically filtered stimuli. The responses of 32 such single neurons were measured to faces which were digitized, lowpass filtered at spatial frequencies of 2, 4, 8,...128 cycles/face, highpass filtered at frequencies of 4, 8,...64 cycles/face, and presented in random sequence using a video framestore. It was found that many of the neurons could respond to blurred images of faces, with a mean frequency at half-maximum amplitude of the neuronal response to the series of lowpass filtered images of faces of 3.3 cycles/face. Almost all the neurons had lowpass cutoff frequencies defined in this way below 8 cycles/face. Many of the neurons could also respond to images of faces in which the only information remaining was a limited amount of high spatial frequency edge information. The mean frequency at half-maximum amplitude of the neuronal response to the series of highpass filtered images of faces was 29.7 cycles/face. Almost all the neurons had highpass cutoff frequencies above 8 cycles/face. Thus, many of the neurons could respond to a lowpass and a highpass filtered image of a face even when these had no spatial frequencies in common. The mean separation between the lowpass and highpass cutoff frequencies was 3.2 octaves. For comparison, face recognition in man can be performed with images which contain only information up to 8 cycles/face, or with highpass filtered images which contain only information down to 8 cycles/face. The response of the neurons was not always a smooth function of frequency, but could decrease as higher frequencies were included in the lowpass filtered images of faces, or as low frequencies were included in the highpass filtered images of faces. This indicates that information in certain frequency bands was able to inhibit these neurons. This was particularly likely to occur for the non-optimal face stimulus for a given neuron, indicating that the selectivity of these neurons to different faces was a combination of the excitation produced by some information in faces and inhibition produced by other.

Action Potentials↗
PubMed1990

Unawareness of impaired face recognition.

We report investigations of the face processing abilities of SP, a right-handed woman who had suffered a subarachnoid haemorrhage from a right middle cerebral artery aneurysm. Although she could correctly assign visual stimuli to the 'face' category without difficulty, SP performed poorly on all other face processing, tasks, including 'closure' (Mooney faces), perception of facial expression, unfamiliar face matching, and identification of familiar faces. Identification of familiar people from nonfacial cues (names) remained relatively well-preserved, but severe impairments were evident on all face recognition tasks. Her errors mostly involved either failures to find a face familiar at all, or misidentification as another familiar person. In face-name learning tasks, there was evidence of 'covert' recognition of faces she failed to recognize overtly. SP's face processing impairment remained stable across a 20-month period of investigation, yet throughout this period she did not think that she had any problems in face recognition, and continued to show lack of insight into this impairment even when directly confronted with its consequences on formal testing. In contrast, SP showed adequate insight into other physical and cognitive impairments produced by her illness, including poor memory, hemiplegia, and hemianopia. We propose that her lack of insight into her face recognition problems involves a deficit-specific anosognosia, resulting from impairment of domain-specific monitoring abilities.

Agnosia↗
PubMed2006

Is high-spatial frequency information used in the early stages of face detection?

The present study examined the role of high-spatial frequency information in early face processing, as indexed by the N170 face-sensitive ERP component. Participants detected 4 versions of famous faces, including full spectrum faces, and bandpass filtered faces containing predominantly high-spatial frequencies, low-spatial frequencies or both. The power spectra of all stimuli were balanced by superimposing the faces onto a visual noise background that included the spatial frequency information that was missing in filtered faces, e.g., high-spatial frequency faces were presented on a high- and low-spatial frequency background. An additional condition comprising of filtered visual noise only was also created to ensure that any observed effects were related to the processing of faces and not simply due to variations between spatial frequency information. Both behavioral and electrophysiological results replicated previous findings of a low-spatial frequency advantage for face processing. However, our results also show that faces containing both high and low-spatial frequency information are detected faster and more accurately than faces containing predominantly low-spatial frequencies. Furthermore, this advantage occurred with an enhanced amplitude of the N170. Together, these findings refute the suggestion that high-spatial frequencies are redundant in face perception.

Adult↗
PubMed2004

Sex differences in face gender recognition in humans.

Human faces are ecologically-salient stimuli. Face sex is particularly relevant for human interactions and face gender recognition is an extremely efficient cognitive process that is acquired early during childhood. To measure the minimum information required for correct gender classification, we have used a pixelation filter and reduced frontal pictures (28,672 pixels) of male and female faces to 7168, 1792, 448 and 112 pixels. We then addressed the following questions: Is gender recognition of male and female faces equally efficient? Are male and female subjects equally efficient at recognising face gender? We found a striking difference in categorisation of male and female faces. Categorisation of female faces reduced to 1792 pixels is at chance level whereas categorisation of male faces is above chance even for 112 pixel images. In addition, the same difference in the efficiency of categorisation of male and female faces was detected using a Gaussian noise filter. A clear sex difference in the efficiency of face gender categorisation was detected as well. Female subject were more efficient in recognising female faces. These results indicate that recognition of male and female faces are different cognitive processes and that in general females are more efficient in this cognitive task.

Adolescent↗
PubMed2004

Regional brain response to faces of humans and dogs.

The extent to which the brain regions associated with face processing are selective for that specific function remains controversial. In addition, little is known regarding the extent to which face-responsive brain regions are selective for human faces. To study regional selectivity of face processing, we used functional magnetic resonance imaging to examine whole brain activation in response to human faces, dog faces, and houses. Fourteen healthy right-handed volunteers participated in a passive viewing, blocked experiment. Results indicate that the lateral fusiform gyrus (Brodmann's area 37) responds maximally to both dog and human faces when compared with other sites, followed by the middle/inferior occipital gyrus (BA 18/19). Sites that were activated by houses versus dog and human faces included the medial fusiform gyrus (BA 19/37), the posterior cingulate (BA 30), and the superior occipital gyrus (BA 19). The only site that displayed significant differences in activation between dog and human faces was the lingual/medial fusiform gyrus. In this site, houses elicited the strongest activation, followed by dog faces, while the response to human faces was negligible and did not differ from fixation. The parahippocampal gyrus/amygdala was the sole site that displayed significant activation to human faces, but not to dog faces or houses.

Adolescent↗
PubMed2005

The neural basis of the behavioral face-inversion effect.

Two of the most robust markers for "special" face processing are the behavioral face-inversion effect (FIE)-the disproportionate drop in recognition of upside-down (inverted) stimuli relative to upright faces-and the face-selective fMRI response in the fusiform face area (FFA). However, the relationship between these two face-selective markers is unknown. Here we report that the behavioral FIE is closely associated with the fMRI response in the FFA, but not in other face-selective or object-selective regions. The FFA and the face-selective region in the superior temporal sulcus (f_STS), but not the occipital face-selective region (OFA), showed a higher response to upright than inverted faces. However, only in the FFA was this fMRI-FIE positively correlated across subjects with the behavioral FIE. Second, the FFA, but not the f_STS, showed greater neural sensitivity to differences between faces when they were upright than inverted, suggesting a possible neural mechanism for the behavioral FIE. Although a similar trend was found in the occipital face area (OFA), it was less robust than the FFA. Taken together, our data suggest that among the face-selective and object-selective regions, the FFA is a primary neural source of the behavioral FIE.

Face↗
PubMed2005

Processing of famous faces and medial temporal lobe event-related potentials: a depth electrode study.

The present study aims at analyzing the modulation of two types of event-related potentials originating from the human medial temporal lobe, the rhinal AMTL-N400 and the hippocampal P600 by the processing of famous faces. Therefore, we used a face recognition paradigm in which subjects had to discriminate the faces of famous persons from the faces of non-famous persons. Eleven patients with unilateral medial temporal lobe epilepsy undergoing intrahippocampal depth electrode recording for presurgical evaluation participated in this study. Event-related potentials (ERP) were recorded while a sequence of famous and non-famous faces was presented to the patients. The presentation of each face was repeated. The faces evoked N400-like potentials (anterior medial temporal lobe N400, AMTL-N400) in the rhinal cortex and P600-like potentials in the hippocampus. ERPs elicited by famous faces were contrasted with ERPs elicited by non-famous faces. The first presentation of famous faces elicited an enhanced AMTL-N400 and an enhanced hippocampal P600 in comparison to the second presentations of the famous faces or the (first and second presentation of the) non-famous faces. This findings are discussed in terms of associative semantic memory processes and the retrieval of person-specific information from long-term memory stores triggered by the processing of famous faces.

Adult↗
PubMed2004

Haptic face recognition and prosopagnosia.

Cases of cross-modal influence have been observed since the beginning of psychological science. Yet some abilities like face recognition are traditionally only investigated in the visual domain. People with normal visual face-recognition capacities identify inverted faces more poorly than upright faces. An abnormal pattern of performance with inverted faces by prosopagnosic individuals is characteristically interpreted as evidence for a deficit in configural processing essential for normal face recognition. We investigated whether such problems are unique to vision by examining face processing by hand in a prosopagnosic individual. We used the haptic equivalent of the visual-inversion paradigm to investigate haptic face recognition. If face processing is specific to vision, our participant should not show difficulty processing faces haptically and should perform with the same ease as normal controls. Instead, we show that a prosopagnosic individual cannot haptically recognize faces. Moreover, he shows similar abnormal inversion effects by hand and eye. These results suggest that face-processing deficits can be found across different input modalities. Our findings also extend the notion of configural processing to haptic face and object recognition.

Discrimination, Psychological↗
PubMed2005

Normal and abnormal face selectivity of the M170 response in developmental prosopagnosics.

Developmental prosopagnosia is a lifelong impairment in face recognition despite normal low-level visual processing. Here we used magnetoencephalography (MEG) to examine the M170 response, a component occurring approximately 170 ms after stimulus onset, in a group of five developmental prosopagnosics. In normal subjects, the M170 is "face-selective", with a consistently higher amplitude to faces than to a wide variety of other visual stimulus categories; the N170, a component recorded using event-related potentials (ERP) and thought to be analogous to the M170, also shows this "face selectivity". Two previous ERP studies with developmental prosopagnosics have found attenuation or absence of face selectivity in the N170 response of these subjects [Bentin, S., Deouell, L. Y., and Soroker, N. (1999). Selective visual streaming in face recognition: Evidence from developmental prosopagnosia. Neuroreport, 10, 823-827; Kress, T., and Daum, I. (2003). Event-related potentials reflect impaired face recognition in patients with congenital prosopagnosia. Neuroscience Letters, 352, 133-136]. Three of our developmental prosopagnosic group showed this non-selective pattern at the M170 while the remaining two prosopagnosics were indistinguishable from normal controls. Thus, impaired face recognition is not necessarily correlated with an absence of the "face-selective" M170. Furthermore, ERP recordings collected simultaneously in the two developmental prosopagnosics with seemingly selective M170s also showed N170s within the same normal selective range, demonstrating that the face-selective signals found with MEG are not due to differences between MEG and ERP. While the presence of face selectivity at these neurophysiological markers is insufficient for predicting normal behavioral performance with faces, it could help to distinguish different classes of face recognition deficits.

Adult↗
PubMed2006

Spontaneous retrieval of affective person knowledge in face perception.

In a functional magnetic resonance imaging experiment, we explored whether affective person knowledge based on memories formed from minimal information is spontaneously retrieved in face perception. In the first stage of the experiment, participants were presented with 120 unfamiliar faces. Each face was presented with a description of one of four types of behaviors: aggressive, disgusting, neutral, and nice. In the second stage, participants were scanned while engaged in a one-back recognition task in which they saw the faces that were associated with behaviors and 30 novel faces. Although this task is a simple perceptual task that neither demands person evaluation nor retrieval of person knowledge, neural responses to faces differed as a function of the behaviors. Faces associated with behaviors evoked stronger activity than did novel faces in regions implicated in social cognition--anterior paracingulate cortex and superior temporal sulcus. Explicit memory for the behaviors enhanced the neural response in these regions. Faces associated with disgusting behaviors evoked stronger activity in left anterior insula than did faces associated with aggressive behaviors. This effect was equally strong for faces associated with explicitly recalled behaviors and faces associated with non-recalled behaviors. The findings suggest that affective person knowledge acquired from minimal information is spontaneously retrieved in face perception, engaging neural systems for analysis of social cognition and emotions.

Adolescent↗
PubMed2005

The nature of synthetic face adaptation.

Recent evidence demonstrates that adapting to a face will systematically bias the perception of faces that lie along the same identity trajectory in geometric face space but not faces that lie along different identity trajectories. We explored this configural aftereffect using synthetic face stimuli developed to measure face-specific processing. Adapting to synthetic "anti-faces" resulted in an identity-specific aftereffect that was characterized by a marked decrease in the slope of the psychometric functions. Adaptation transferred across different face sizes, but not different face viewpoints nor faces constructed about a non-mean face. Performance was captured by a model where responses were modulated through a divisive gain control and an additive constant reflecting a shift in the origin of perceived face space. Together, these results suggest that face adaptation reflects activity from mechanisms common to various processing stages along the visual pathway.

Adaptation, Biological↗