Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Time Perception”

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 649 records · Page 36Linked to original sources
PubMed2006

Speech perception and short-term memory deficits in persistent developmental speech disorder.

Children with developmental speech disorders may have additional deficits in speech perception and/or short-term memory. To determine whether these are only transient developmental delays that can accompany the disorder in childhood or persist as part of the speech disorder, adults with a persistent familial speech disorder were tested on speech perception and short-term memory. Nine adults with a persistent familial developmental speech disorder without language impairment were compared with 20 controls on tasks requiring the discrimination of fine acoustic cues for word identification and on measures of verbal and nonverbal short-term memory. Significant group differences were found in the slopes of the discrimination curves for first formant transitions for word identification with stop gaps of 40 and 20 ms with effect sizes of 1.60 and 1.56. Significant group differences also occurred on tests of nonverbal rhythm and tonal memory, and verbal short-term memory with effect sizes of 2.38, 1.56, and 1.73. No group differences occurred in the use of stop gap durations for word identification. Because frequency-based speech perception and short-term verbal and nonverbal memory deficits both persisted into adulthood in the speech-impaired adults, these deficits may be involved in the persistence of speech disorders without language impairment.

Adolescent↗
PubMed2005

Auditory temporal information processing in preschool children at family risk for dyslexia: relations with phonological abilities and developing literacy skills.

In this project, the hypothesis of an auditory temporal processing deficit in dyslexia was tested by examining auditory processing in relation to phonological skills in two contrasting groups of five-year-old preschool children, a familial high risk and a familial low risk group. Participants were individually matched for gender, age, non-verbal IQ, school environment, and parental educational level. Psychophysical thresholds were estimated for gap-detection, frequency modulation detection, and tone-in-noise detection using a three-interval forced-choice adaptive staircase paradigm embedded within a computer game. Phonological skills were measured by tasks assessing phonological awareness, rapid serial naming, and verbal short-term memory. Significant group differences were found for phonological awareness and letter knowledge. In contrast, none of the auditory tasks differentiated significantly between both groups. However, both frequency modulation and tone-in-noise detection were significantly related to phonological awareness. This relation with phonological skills was not present for gap-detection.

Child, Preschool↗
PubMed2004

Medial prefrontal cortex is involved in spatial temporal order memory but not spatial recognition memory in tests relying on spontaneous exploration in rats.

The present study describes two novel tasks relying on spontaneous patterns of exploration in a radial-arm maze that can be used to assess spatial recognition memory and spatial temporal order memory (i.e. memory for the order in which places have been visited) in the rat. In the recognition memory task, rats were permitted to freely explore two arms in the maze on a first trial and one 'familiar' arm and one novelly located arm on a second trial 105 min later. In the temporal order memory task, rats were permitted to explore two arms in the maze on a first trial, two novel arms on a second trial 60 min later, and one 'older familiar' arm and one 'more recent familiar' arm on a third trial 45 min later. Using these tasks, we found that rats direct greater exploration at a novel than a familiar arm location, thus showing long-term spatial recognition memory, and at an older familiar arm than a more recent familiar arm, thus showing long-term spatial temporal order memory. Lidocaine inactivation of the mPFC prior to the final trial in each task disrupted performance on the temporal order but not the recognition memory task, thereby demonstrating a role for the mPFC in the retrieval and/or use of temporal order information but not in spatial memory per se. These findings highlight the specific involvement of the rat mPFC in temporal order memory and have important implications for a broader understanding of mPFC function.

Analysis of Variance↗
PubMed2006

Double dissociation between hippocampal and prefrontal lesions on an operant delayed matching task and a water maze reference memory task.

The hippocampus and prefrontal cortex have both been implicated in various aspects of the acquisition, retention and performance of delayed matching to position (DMTP) tasks in the rat, although their precise respective contributions remain unclear. In the present study, rats were trained preoperatively on DMTP before receiving excitotoxic bilateral lesions of either the entire hippocampus or the medial prefrontal cortex. Rats with lesions of the prefrontal cortex exhibited a significant delay-dependent impairment on retention of the DMTP task, whereas hippocampal lesions were without effect. Rats were also exposed to a switch in the contingencies to a 'non-matching' rule, as an analogue of switching between decision rules in the human Wisconsin Card Sorting Test, in which human patients with prefrontal damage are impaired. Both lesion groups acquired the new contingency at control levels, providing no evidence towards a role for either of these areas in this type of rule-switching. The same rats were also assessed in a spatial reference memory task in the water maze, which revealed an impairment in escape latencies and path length that was specific to the hippocampal lesions. The results corroborate previous evidence that the hippocampus is not necessary for at least some aspects of working memory performance in the DMTP task, whereas the delay-dependent deficit in the prefrontal lesion group support this task as a potentially powerful tool for assessing the cognitive changes associated with frontal damage and repair.

Animals↗
PubMed2005

The perception of empty and filled time intervals by rats.

In Experiment 1, rats were trained in a within-subjects design to discriminate durations of a filled interval, and durations of an empty interval (an unfilled interval marked at the beginning and end by a 500 ms tone). Training and psychophysical testing was conducted with three sets of anchor durations. Rats made more long responses for filled than for empty intervals at signal durations greater than the geometric mean. In Experiment 2, Group Same was trained similarly to the rats in Experiment 1 with the ambient conditions (house light illumination) remaining the same during the intertrial interval and the empty intervals. Group Different was trained with the house light turned off during empty and filled intervals. The similarity of ambient conditions during the intertrial interval and the empty intervals did not significantly affect timing. Filled intervals were timed more precisely and they were perceived as longer than empty intervals of the same duration. The psychophysical functions superimposed across anchor duration sets. These results are the first clear evidence of a filled interval illusion in rats, and they suggest that this difference may reflect a clock rate effect (greater for filled intervals) rather than a switch latency effect (slower for empty intervals).

Animals↗
PubMed2006

Combined organizational and activational effects of short and long photoperiods on spatial and temporal memory in rats.

The present study examined the effects of photoperiod on spatial and temporal memory in adult Sprague-Dawley rats that were conceived and reared in different day lengths, i.e., short day (SD-8:16 light/dark) and long day (LD-16:8 light/dark). Both male and female LD rats demonstrated increased spatial memory capacity as evidenced by a lower number of choices to criterion in a 12-arm radial maze task relative to the performance of SD rats. SD rats also demonstrated a distortion in the content of temporal memory as evidenced by a proportional rightward shift in the 20 and 60 s temporal criteria trained using the peak-interval procedure that is consistent with reduced cholinergic function. The conclusion is that both spatial and temporal memory are sensitive to photoperiod variation in laboratory rats in a manner similar to that previously observed for reproductive behaviour.

Analysis of Variance↗
PubMed2006

Audiovisual synchrony perception for music, speech, and object actions.

We investigated the perception of synchrony for complex audiovisual events. In Experiment 1, a series of music (guitar and piano), speech (sentences), and object action video clips were presented at a range of stimulus onset asynchronies (SOAs) using the method of constant stimuli. Participants made unspeeded temporal order judgments (TOJs) regarding which stream (auditory or visual) appeared to have been presented first. Temporal discrimination accuracy was significantly better for the object actions than for the speech video clips, and both were significantly better than for the music video clips. In order to investigate whether or not these differences in TOJ performance were driven by differences in stimulus familiarity, we conducted a second experiment using brief speech (syllables), music (guitar), and object action video clips of fixed duration together with temporally reversed (i.e., less familiar) versions of the same stimuli. The results showed no main effect of stimulus type on temporal discrimination accuracy. Interestingly, however, reversing the video clips resulted in a significant decrement in temporal discrimination accuracy as compared to the normally presented for the music and object actions clips, but not for the speech stimuli. Overall, our results suggest that cross-modal temporal discrimination performance is better for audiovisual stimuli of lower complexity as compared to stimuli having continuously varying properties (e.g., syllables versus words and/or sentences).

Acoustic Stimulation↗
PubMed2005

Brain mechanisms underlying perceptual causality.

Functional magnetic resonance imaging (fMRI) was used to examine the neural correlates of perceptual causality. Participants were imaged while viewing alternating blocks of causal events in which a ball collides with, and causes movement of another ball, versus non-causal events in which a spatial or a temporal gap precedes the movement of a second ball. There were significantly higher levels of relative activation in the right middle frontal gyrus and the right inferior parietal lobule for causal relative to non-causal events. Furthermore, when the differential effects of spatial and temporal incontiguities were subtracted from the contiguous stimuli, we observed both common (right prefrontal) and unique (right parietal and right temporal) regions of activation as a function of spatial and temporal processing of contiguity, respectively. Taken together, these data provide a means to help determine how the visual system extracts causality from dynamic visual information in the environment using spatial and temporal cues.

Adult↗
PubMed2006

Representing episodes in the mammalian brain.

Memory lets the past inform the present so that we can attain future goals. In many species, these abilities require the hippocampus. Recent experiments, in which memory demand was varied while overt behavior and the environment were kept constant, have revealed firing patterns of hippocampal neurons that corresponded with memory demands and predicted performance. Although the active population appeared to be 'place cells' that signalled location, it actually included cells the activity patterns of which distinguished the recent or pending history of behavior during identical actions that occurred in the same place. Different populations of hippocampal cells fired as a rat walked along the same spatial path on the way to different goals, and coded past, present and pending events. Other experiments provide converging data that neuronal activity is modulated by goal-directed behavioral episodes. Together, these firing patterns suggest a testable mechanism of episodic memory coding: that hippocampal dynamics encode a temporally extended, hierarchically organized representation of goal-directed behavior.

Action Potentials↗
PubMed2004

A dose-effect study of repeated administration of buprenorphine/naloxone on performance in opioid-dependent volunteers.

Based on its unique pharmacological profile, buprenorphine may produce less impairment in psychomotor and cognitive performance than methadone. However, the few studies that have investigated the performance effects of buprenorphine in opioid-abusing volunteers examined effects of single acute doses rather than effects of repeated dosing and included a very limited range of measures. The present inpatient study evaluated dose-related effects of repeated administration of the buprenorphine/naloxone combination product (8/2, 16/4, 32/8 mg, sublingual tablets) in eight opioid-dependent volunteers on performance of a broad range of tasks, following a period of 7-10 days of dosing at each level, in a double-blind, within-subject, crossover design. The testing battery included measures of psychomotor speed, time perception, conceptual flexibility, focused attention, working memory, long-term/episodic memory, and metamemory. Supporting the hypothesis of limited impairment with buprenorphine, results revealed minimal impairment in performance as buprenorphine/naloxone dose was increased four-fold. The only significant effect of dose was an impairment in episodic/long-term memory (recognition memory) performance at the highest dose (32/8 mg) relative to the two lower doses. Future studies incorporating larger sample sizes and non-drug controls, as well as directly comparing buprenorphine to methadone and LAAM are needed to further test the hypothesis of limited impairment with buprenorphine.

Adult↗
PubMed2006

A dense array stimulator to generate arbitrary spatio-temporal tactile stimuli.

The generation and presentation of tactile stimuli presents a unique challenge. Unlike vision and audition, in which standard equipment such as monitors and audio systems can be used for most experiments, tactile stimuli and/or stimulators often have to be tailor-made for a given study. Here, we present a novel tactile stimulator designed to present arbitrary spatio-temporal stimuli to the skin. The stimulator consists of 400 pins, arrayed over a 1cm(2) area, each under independent computer control. The dense array allows for an unprecedented number of stimuli to be presented within an experimental session (e.g., up to 1200 stimuli per minute) and for stimuli to be generated adaptively. The stimulator can be used in a variety of modes and can deliver indented and scanned patterns as well as stimuli defined by mathematical spatio-temporal functions (e.g., drifting sinusoids). We describe the hardware and software of the system, and discuss previous and prospective applications.

Brain Mapping↗
PubMed2004

Perceptual and motor contributions to bimanual coordination.

Following earlier work by Mechsner et al. (Nature 414 (2001) 69), the purpose of this experiment was to determine the perceptual and motoric contributions to bimanual coordination. Twenty right-handed, healthy, young adults performed continuous, horizontal, linear movements of both upper limbs at frequencies of 1.5 and 2.0 Hz. The goal was to control the spatial-temporal displacement of two flags by coordinating upper limb movements in two perceptual conditions. In a congruent condition, the movement of the flags matched the movement of the upper limbs. In an incongruent condition, the movement of the flags was opposite to the movement of the upper limbs. Measures of error in coordination provided support primarily for a motor view of bimanual coordination, and failed to replicate the earlier findings of Mechsner et al.

Adult↗
PubMed2004

The role of the human ventromedial prefrontal cortex in memory for contextual information.

There is a growing body of evidence that the ventromedial prefrontal cortex (VMPFC) is implicated in the new learning of visual items. Little is known, however, as to the involvement of that portion of the prefrontal cortex in the learning of temporal and spatial relationship of those items. The aim of the present study, therefore, was to investigate the role of the VMPFC in memory for temporal and spatial order. Patients who had undergone surgery of the anterior communicating artery aneurysm, and normal control subjects (C), participated in the study. The patients were subdivided into three groups: with resection of the left (LGR+) or right (RGR+) gyrus rectus, and without such a resection (GR-). Subjects were presented with two memory tests: a temporal order (TO) test and a spatial order (SO) test. In the TO test, the LGR+ and RGR+ groups performed worse than the C group, while the GR- group did not differ significantly from the C group. In the SO test, the LGR+ and RGR+ groups did not differ significantly from the C and GR- groups. However, the trend appears to be the same for both tests, although only the TO test provides statistically significant group differences. Our results thus suggest that the VMPFC is involved in memory for contextual information. Together with previous findings, the data suggest that the learning of the relationship between items as well as the learning of those items are mediated by overlapping areas of the VMPFC.

Aneurysm, Ruptured↗
PubMed2006

Evaluating the influence of frame rate on the temporal aspects of audiovisual speech perception.

We investigated whether changing the frame rate at which speech video clips were presented (6-30 frames per second, fps) would affect audiovisual temporal perception. Participants made unspeeded temporal order judgments (TOJs) regarding which signal (auditory or visual) was presented first for video clips presented at a range of different stimulus onset asynchronies (SOAs) using the method of constant stimuli. Temporal discrimination accuracy was unaffected by changes in frame rate, while lower frame rate speech video clips required larger visual-speech leads for the point of subjective simultaneity (PSS) to be achieved than did higher frame rate video clips. The significant effect of frame rate on temporal perception demonstrated here has not been controlled for in previous studies of audiovisual synchrony perception using video stimuli and is potentially important given the rapid increase in the use of audiovisual videos in cognitive neuroscience research in recent years.

Acoustic Stimulation↗
PubMed2006

Electrical brain imaging reveals spatio-temporal dynamics of timbre perception in humans.

Timbre is a major attribute of sound perception and a key feature for the identification of sound quality. Here, we present event-related brain potentials (ERPs) obtained from sixteen healthy individuals while they discriminated complex instrumental tones (piano, trumpet, and violin) or simple sine wave tones that lack the principal features of timbre. Data analysis yielded enhanced N1 and P2 responses to instrumental tones relative to sine wave tones. Furthermore, we applied an electrical brain imaging approach using low-resolution electromagnetic tomography (LORETA) to estimate the neural sources of N1/P2 responses. Separate significance tests of instrumental vs. sine wave tones for N1 and P2 revealed distinct regions as principally governing timbre perception. In an initial stage (N1), timbre perception recruits left and right (peri-)auditory fields with an activity maximum over the right posterior Sylvian fissure (SF) and the posterior cingulate (PCC) territory. In the subsequent stage (P2), we uncovered enhanced activity in the vicinity of the entire cingulate gyrus. The involvement of extra-auditory areas in timbre perception may imply the presence of a highly associative processing level which might be generally related to musical sensations and integrates widespread medial areas of the human cortex. In summary, our results demonstrate spatio-temporally distinct stages in timbre perception which not only involve bilateral parts of the peri-auditory cortex but also medially situated regions of the human brain associated with emotional and auditory imagery functions.

Acoustic Stimulation↗
PubMed2005

Deficits in temporal-order judgments in dyslexia: evidence from diotic stimuli differing spectrally and from dichotic stimuli differing only by perceived location.

The main debate concerning dyslexia focuses on the question of whether dyslexia is a language-specific disorder or a general nervous system dysfunction manifested in deficits of temporal processing. According to the temporal-order deficit hypothesis, dyslexia manifests difficulty in discriminating the temporal order of stimuli. Evidence has usually involved testing the ability to discriminate series of phonemes or pure tones whose components are separated by very short intervals. One of the difficulties in interpreting the data is the confound of changes in the spectrum with changes in temporal order. Two experiments are reported. In the first experiment, we verified the difficulty by adult dyslexics in judging the temporal order of two tones differing in frequency and presented diotically. The second experiment was designed to isolate temporal-order judgment (TOJ) from holistic frequency-based pattern discrimination processes. We tested temporal-order judgments with 15 ms duration tones of equal frequency presented dichotically (left-right, right-left) with ISI intervals ranging from 8 to 400 ms. Dichotic temporal threshold was significantly lower for adult normal readers than for the adult dyslexics. The results support the claim that adult dyslexics have difficulty in discriminating temporal order even when no spectral changes are involved.

Acoustic Stimulation↗
PubMed2005

Modulation of recognition and temporal order memory retrieval by dopamine D1 receptor in rats.

The present study examines the effects of SKF 81297, a selective D1 agonist, on information retrieval in recognition and temporal order memory for objects, using three different tasks. Separate groups of rats were trained in each task and then given an intraperitoneal injection of saline or the D1 agonist (0.03, 0.3 mg/kg), before the memory testing trial in an object recognition, object location, and object temporal order memory tasks. We show that SKF 81297, at high dose (0.3 mg/kg), facilitates information retrieval after a long delay (4 h) in the three memory tasks whereas both high and low doses of D1 agonist impair recognition memory after a short delay (15 min). These results indicate a significant role of dopamine D1 receptors in recognition memory for both familiarity and place of objects in addition to object temporal order memory.

Analysis of Variance↗
PubMed2005

Disruption of delayed memory for a sequence of spatial locations following CA1- or CA3-lesions of the dorsal hippocampus.

Axon-sparing neurotoxic lesions of CA1 or CA3 were produced in the dorsal hippocampus to test dissociative lesion effects on spatial working memory for sequential items. Rats were required to remember four different sections sequentially presented on a newly devised maze (i.e., Tulum maze) during a study phase. Each section was cued by a unique object that was specifically associated with each location within the section during the study phase. Following a 15-s delay and during the test phase, rats were required to revisit the location within a section randomly chosen among the previously visited sections in the absence of the cued object. Both CA1 and CA3 lesions similarly disrupted accurate relocation of a previously visited place. However, differential effects of the CA1 and CA3 lesions were observed in serial position curves. CA3-lesions disrupted performance for the first three serial positions, but did not disrupt performance for the last serial position (recency). In contrast, CA1-lesions disrupted performance for all serial positions. The results suggest that temporal separation of spatial memory may depend on the conjoint function of CA1 and CA3 of the hippocampus with a disruption of a spatial pattern completion process following CA3 lesions and a disruption of a temporal pattern separation process following a CA1 lesion.

Animals↗