Biomedical subjects

C Neil Macrae

Publications and source records attributed to C Neil Macrae.

At least 19 recordsLinked to original sources

PubMed2007

Triggering the intentional stance.

While humans possess a ready capacity to view a target (biological or otherwise) as an intentional agent (i.e. the 'intentional stance'), the conditions necessary for spontaneously eliciting these mentalizing processes are less well understood. Although research examining people's tendency to construe the motion of geometric shapes as intentional has done much to illuminate this issue, due to methodological limitations (a reliance on subjective self-report) this work has not fully addressed the potentially automatic and obligatory nature of mentalizing. Acknowledging this problem, recent research using prelinguistic infants, neuroimaging technology and methods that avoid explicit self-report all provide unique paths to circumvent this shortcoming. While work of this kind has generally corroborated the results of previous investigations, it has also raised a number of new issues. One such issue is whether spontaneous mentalizing processes for abstract non-biological stimuli are instantiated in the same neural architecture as those for realistic representations of intentional biological agents. This question is considered in the current chapter.

Emotions↗

PubMed2006

Dissociable medial prefrontal contributions to judgments of similar and dissimilar others.

Human social interaction requires the recognition that other people are governed by the same types of mental states-beliefs, desires, intentions-that guide one's own behavior. We used functional neuroimaging to examine how perceivers make mental state inferences when such self-other overlap can be assumed (when the other is similar to oneself) and when it cannot (when the other is dissimilar from oneself). We observed a double dissociation such that mentalizing about a similar other engaged a region of ventral mPFC linked to self-referential thought, whereas mentalizing about a dissimilar other engaged a more dorsal subregion of mPFC. The overlap between judgments of self and similar others suggests the plausibility of "simulation" accounts of social cognition, which posit that perceivers can use knowledge about themselves to infer the mental states of others.

Adult↗

PubMed2006

The distinctiveness effect in forenames: the role of subjective experiences and recognition memory.

We describe two experiments that tested the prediction that distinctive forenames would be better recognized than typical forenames and which investigated whether this distinctiveness effect, if obtained, occurred in subjective experiences of the recollective or familiarity components of recognition memory. To that end, the remember-know paradigm was used to measure people's experiences of recollection or familiarity. The results revealed that distinctive forenames were more memorable than typical forenames and that that this distinctiveness effect was present only in the subjective experience of remembering. Additionally, the present research showed that these distinctiveness effects were present after retention intervals of both 1 and 7 days. These results replicate and extend past research on distinctiveness effects and also provide support for Rajaram's (1996) distinctiveness-fluency account of the 2 states of subjective awareness.

Affect↗

PubMed2005

Forming impressions of people versus inanimate objects: social-cognitive processing in the medial prefrontal cortex.

Recent neuroimaging research has linked the task of forming a "person impression" to a distinct pattern of neural activation that includes dorsal regions of the medial prefrontal cortex (mPFC). Although this result suggests the distinctiveness of social cognition - the processes that support inferences about the psychological aspects of other people - it remains unclear whether mPFC contributions to this impression formation task were person specific or if they would extend to other stimulus targets. To address this unresolved issue, participants in the current study underwent fMRI scanning while performing impression formation or a control task for two types of target: other people and inanimate objects. Specifically, participants were asked to use experimentally-provided information either to form an impression of a person or an object or to intentionally encode the sequence in which the information was presented. Results demonstrated that activation in an extensive region of dorsal mPFC was greater for impression formation of other people than for all other trial types, suggesting that this region specifically indexes the social-cognitive aspects of impression formation (i.e., understanding the psychological characteristics of another mental agent). These findings underscore the extent to which social cognition relies on distinct neural mechanisms.

Adolescent↗

PubMed2005

General and specific contributions of the medial prefrontal cortex to knowledge about mental states.

Recent neuroimaging research (Mitchell, J.P., Heatherton, T.F., Macrae, C.N., 2002. Distinct neural systems subserve person and object knowledge. Proc. Natl. Acad. Sci. U. S. A. 99, 15238-15243.) has suggested that semantic knowledge about the psychological aspects of other people draws on a pattern of neural activity that differentiates social from nonsocial semantics. Although the medial prefrontal cortex (mPFC) clearly plays a central role in a range of such social-cognitive tasks, little is known about the precise contributions made by this region to social semantics. The current study addressed two outstanding questions regarding mPFC function. First, do mPFC contributions to processing words that refer to psychological states extend to other, nonhuman targets or are they specific to understanding the psychological experience of conspecifics? Second, does the mPFC respond generally to tasks that require processing another person, or is its activity specific to understanding psychological characteristics? To address these questions, participants were scanned using fMRI while judging the applicability of words to one of two types of targets: people or dogs. For each target, participants made one of two types of semantic judgment: does this word describe a potential psychological state of the target or does this word refer to a physical part of the target? Results demonstrated that greater mPFC activation accompanied judgments of psychological states than of body parts regardless of whether the target was a person or a dog, indicating that mPFC contributions to social semantics are specific for understanding psychological states--directly countering recent suggestions that mPFC responds generally to any judgment about another person--and that mPFC activity extends to targets other than conspecifics.

Adult↗

PubMed2005

Musical imagery: sound of silence activates auditory cortex.

Auditory imagery occurs when one mentally rehearses telephone numbers or has a song 'on the brain'--it is the subjective experience of hearing in the absence of auditory stimulation, and is useful for investigating aspects of human cognition. Here we use functional magnetic resonance imaging to identify and characterize the neural substrates that support unprompted auditory imagery and find that auditory and visual imagery seem to obey similar basic neural principles.

Acoustic Stimulation↗

PubMed2005

Categorizing others: the dynamics of person construal.

A fundamental question in social cognition is whether people categorize others on the basis of the social groups to which they belong. Integrating ideas from related work on face processing, the current research explored the emergence and boundary conditions of person categorization. Using speeded responses to facial stimuli as a marker of category activation, the authors showed in 3 experiments that person categorization: (a) occurs only under active-encoding conditions and (b) does not extend to applicable but task-irrelevant categorical dimensions, but (c) is sensitive to overlap in the perceptual features that support multiple categorical construals. The authors consider the implications of these findings for models of social-cognitive functioning and the component processes that support person perception.

Adult↗

PubMed2005

The perceptual determinants of person construal: reopening the social-cognitive toolbox.

Guided by a heuristic account of social-cognitive functioning, researchers have attempted to identify the cognitive benefits that derive from a categorical approach to person construal. While revealing, this work has overlooked the fact that, prior to the application of categorical thinking as an economizing mental tool, perceivers must first extract category-triggering information from available stimulus cues. It is possible, therefore, that basic perceptual processes may also contribute to people's propensity to view others in a category-based manner. This possibility was explored in 3 experiments in which the authors investigated the ease with which perceivers can extract categorical and identity-based knowledge from faces under both optimal and suboptimal (i.e., inverted faces, blurred faces, rapidly presented faces) processing conditions. The results confirmed that categorical knowledge is extracted from faces more efficiently than identity-related knowledge, a finding that underscores the importance of perceptual operations in the generation of categorical thinking.

Cognition↗

PubMed2005

Understanding others: the face and person construal.

The face is a critical stimulus in person perception, yet little research has considered the efficiency of the processing operations through which perceivers glean social knowledge from facial cues. Integrating ideas from work on social cognition and face processing, the current research considered the ease with which invariant aspects of person knowledge can be extracted from faces under different viewing and processing conditions. The results of 2 experiments demonstrated that participants extracted knowledge pertaining to the sex and identity of faces in both upright and inverted orientations, even when the faces were irrelevant to the task at hand. The results of an additional experiment, however, suggested that although the extraction of person knowledge from faces may occur unintentionally, the process is nonetheless contingent on the operation of a semantic processing goal. The authors consider the efficiency of person construal and the processes that support this fundamental facet of social-cognitive functioning.

Analysis of Variance↗

PubMed2005

The look of love: gaze shifts and person perception.

Gaze direction is a vital communicative channel through which people transmit information to each other. By signaling the locus of social attention, gaze cues convey information about the relative importance of objects, including other people, in the environment. For the most part, this information is communicated via patterns of gaze direction, with gaze shifts signaling changes in the objects of attention. Noting the relevance of gaze cues in social cognition, we speculated that gaze shifts may modulate people's evaluations of others. We investigated this possibility by asking participants to judge the likability (Experiment 1) and physical attractiveness (Experiment 2) of targets displaying gaze shifts indicative of attentional engagement or disengagement with the participants. As expected, person evaluation was moderated by the direction of gaze shifts, but only when the judgment under consideration was relevant to participants. We consider how and when gaze shifts may modulate person perception and its associated behavioral products.

Adult↗

PubMed2005

The link between social cognition and self-referential thought in the medial prefrontal cortex.

The medial prefrontal cortex (mPFC) has been implicated in seemingly disparate cognitive functions, such as understanding the minds of other people and processing information about the self. This functional overlap would be expected if humans use their own experiences to infer the mental states of others, a basic postulate of simulation theory. Neural activity was measured while participants attended to either the mental or physical aspects of a series of other people. To permit a test of simulation theory's prediction that inferences based on self-reflection should only be made for similar others, targets were subsequently rated for their degree of similarity to self. Parametric analyses revealed a region of the ventral mPFC--previously implicated in self-referencing tasks--in which activity correlated with perceived self/other similarity, but only for mentalizing trials. These results suggest that self-reflection may be used to infer the mental states of others when they are sufficiently similar to self.

Adolescent↗

PubMed2004

Seeing John Malkovich: the neural substrates of person categorization.

Neuroimaging data have implicated regions of the ventral temporal cortex (e.g., fusiform gyrus) as functionally important in face recognition. Recent evidence, however, suggests that these regions are not face-specific, but rather reflect subordinate-level categorical processing underpinned by perceptual expertise. Moreover, when people possess expertise for a particular class of stimuli (e.g., faces), subordinate-level identification is thought to be an automatic process. To investigate the neural substrates of person construal, we used functional magnetic resonance imaging (fMRI) to contrast brain activity while participants judged faces at different levels of semantic specificity (i.e., identity vs. occupation). The results revealed that participants were quicker to access identity than occupational knowledge. In addition, greater activity was observed in bilateral regions of the fusiform gyrus on identity than occupation trials. Taken together, these findings support the viewpoint that person construal is characterized by the ability to access subordinate-level semantic information about people, a capacity that is underpinned by neural activity in discrete regions of the ventral temporal cortex.

Adult↗

PubMed2004

Encoding-specific effects of social cognition on the neural correlates of subsequent memory.

To examine whether social cognition recruits distinct mental operations, we measured brain activity during social ("form an impression of this person") and relatively nonsocial ("remember the order in which person information is presented") orienting tasks. Extending previous research on the neural basis of social cognition, the impression formation task differentially engaged an extensive region of the dorsomedial prefrontal cortex (PFC). In contrast, the nonsocial sequencing task differentially engaged the superior frontal and parietal gyri, precentral gyrus, and the caudate. In addition, we compared encoding activations for subsequently remembered (i.e., hits) to subsequently forgotten (i.e., misses) items. The brain regions in which the blood oxygenation level-dependent signal distinguished subsequent hits from subsequent misses depended on which orienting task was performed at encoding: subsequent memory was correlated with encoding activity only in the medial PFC for impression formation trials but in the right hippocampus for sequencing trials. These data inform two interrelated cognitive issues. First, results underscore the neuroanatomical distinctiveness of social cognition and suggest that previous psychological theories may have neglected important functional differences in how the human brain instantiates social and nonsocial cognitive processes. Second, by demonstrating that activity in different brain regions correlates with subsequent memory as a function of the orienting task performed at encoding, these data provide evidence of the neural basis for encoding specificity, the principle that memory is critically determined by the cognitive process engaged by the initial study episode.

Adult↗

PubMed2004

Medial prefrontal activity predicts memory for self.

The ability to remember the past depends on cognitive operations that are recruited when information is initially encountered. In the current experiment, we investigated neural processes that subserve the memorability of a fundamental class of social information: self-knowledge. Participants evaluated the extent to which a series of personality characteristics were self-descriptive. Brain activation was measured using event-related functional magnetic resonance imaging (fMRI) and contrasted based on: (i) whether each word was later remembered or forgotten; and (ii) whether or not each item was judged to be self-relevant. Results revealed that activity in medial prefrontal cortex predicted both subsequent memory performance and judgements of self-relevance. These findings extend current understanding of the nature and functioning of human memory.

Adult↗

PubMed2004

From facial cue to dinner for two: the neural substrates of personal choice.

The current experiment examined the neural substrates of response selection, comparing conditions that required participants to make criterion-free selections from sets of same-sex faces (i.e., inconsequential decision) to choosing a dinner date from opposite-sex faces (i.e., consequential decision). In each of these tasks, either a single face (i.e., no choice) or two or three faces (i.e., free choice) appeared for selection. The results revealed that regions of dorsal premotor cortex (PMd) and parietal cortex bilaterally, as well as an area along the medial surface of the superior frontal gyrus, were activated by both consequential and inconsequential decisions, thereby providing evidence for a common selection network. Consequential decisions were further indexed by activation of the insula/ventrolateral prefrontal cortex (BA 47) and the paracingulate gyrus (BA 32). The implications of these findings for current accounts of response selection and social-cognitive functioning are considered.

Adult↗

PubMed2004

Look into my eyes: gaze direction and person memory.

The current research considered the effects of gaze direction on a fundamental aspect of social cogition: person memory. It was anticipated that a person's direction of gaze (i.e., direct or averted) would impact his or her subsequent memorability, such that recognition would be enhanced for targets previously displaying direct gaze. In Experiment 1, participants were presented with faces displaying either direct or averted gaze in a person-classification (i.e., conceptual) task. Then, in a surprise memory test, they were required to report whether a presented face had been seen before. As expected, a recognition advantage was observed for targets displaying direct gaze during the initial classification task. This finding was replicated and extended in a second experiment in which participants initially reported the spatial location (i.e., perceptual task) of each face. We consider the implications of these findings for basic aspects of social-cognitive functioning and person perception.

Adolescent↗

PubMed2004

Thinking about actions: the neural substrates of person knowledge.

Despite an extensive literature on the neural substrates of semantic knowledge, how person-related information is represented in the brain has yet to be elucidated. Accordingly, in the present study we used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of person knowledge. Focusing on the neural substrates of action knowledge, participants reported whether or not a common set of behaviors could be performed by people or dogs. While dogs and people are capable of performing many of the same actions (e.g. run, sit, bite), we surmised that the representation of this knowledge would be associated with distinct patterns of neural activity. Specifically, person judgments were expected to activate cortical areas associated with theory of mind (ToM) reasoning. The results supported this prediction. Whereas action-related judgments about dogs were associated with activity in various regions, including the occipital and parahippocampal gyri; identical judgments about people yielded activity in areas of prefrontal cortex, notably the right middle and medial frontal gyri. These findings suggest that person knowledge may be functionally dissociable from comparable information about other animals, with action-related judgments about people recruiting neural activity that is indicative of ToM reasoning.

Adolescent↗

PubMed2004

Categorizing and individuating others: the neural substrates of person perception.

People are remarkably adroit at understanding other social agents. Quite how these information-processing abilities are realized, however, remains open to debate and empirical scrutiny. In particular, little is known about basic aspects of person perception, such as the operations that support people's ability to categorize (i. e., assign persons to groups) and individuate (i. e., discriminate among group members) others. In an attempt to rectify this situation, the current research focused on the initial perceptual stages of person construal and considered: (i) hemispheric differences in the efficiency of categorization and individuation; and (ii) the neural activity that supports these social-cognitive operations. Noting the greater role played by configural processing in individuation than categorization, it was expected that performance on the former task would be enhanced when stimuli (i. e., faces) were presented to the right rather than to the left cerebral hemisphere. The results of two experiments (Experiment 1--healthy individuals; Experiment 2--split-brain patient) confirmed this prediction. Extending these findings, a final neuroimaging investigation revealed that individuation is accompanied by neural activity in regions of the temporal and prefrontal cortices, especially in the right hemisphere. We consider the implications of these findings for contemporary treatments of person perception.

Brain Mapping↗