Odour perception: an object-recognition approach

Object recognition is a crucial component of both visual and auditory perception. It is also critical for olfaction. Most odours are composed of 10s or 100s of volatile components, yet they are perceived as unitary perceptual events against a continually shifting olfactory background (i.e. figure-ground segregation). We argue here that this occurs by rapid central adaptation to background odours combined with a pattern-matching system to recognise discrete sets of spatial and temporal olfactory features-an odour object. We present supporting neuropsychological, learning, and developmental evidence and then describe the neural circuitry which underpins this. The vagaries of an object-recognition approach are then discussed, with emphasis on the putative importance of memory, multimodal representations, and top-down processing.     

Gender Role Beliefs and Attitudes toward Lesbians and Gay Men in Chile and the U.S.

We compared the relationship between gender role beliefs and antigay prejudice in Chile and the United States. Participants were Chilean and American university students. In Study 1, Chileans were more prejudiced than Americans, and men were more prejudiced than women. In Study 2, gender role beliefs mediated cultural and sex differences in prejudice. Chileans held more traditional gender role beliefs and were more antigay than Americans. Men were more prejudiced than women, particularly in their attitudes toward gay men. Further, sex differences in attitudes toward lesbians and gay men were completely mediated by gender role beliefs. Nationality differences in attitudes toward lesbians were completely mediated, and nationality differences in attitudes toward gay men were partially mediated, by gender role beliefs.     

The association of depression and sense of belonging with suicidal ideation among older adults: applicability of resiliency models

Suicide among older people, especially men, is a significant problem. In this study the applicability of the compensatory, the risk-protective, the challenge, and the protective-protective models of resiliency for the prediction of suicidal ideation from depression (the risk factor) and sense of belonging to the community (the protective factor) was investigated. A total of 351 retired Australians (130 males and 221 females), with a mean age of 71.31 years (SD = 7.99), completed the Zung Depression Scale, the suicide subscale of the General Health Questionnaire, and the Sense of Belonging Instrument. When sense of belonging (psychological) was the protective factor, results indicated support for the risk-protective model for men and women, and for the compensatory model for women only. In contrast, when sense of belonging (antecedents) was the protective factor, support was evident for the compensatory model for men and women, and for the challenge model for women only. Results indicate that interventions should be developed to enhance sense of belonging among aging adults.     

The role of attentional biases in PTSD: is it interference or facilitation?

Although attentional biases have been demonstrated in individuals with posttraumatic stress disorder (PTSD), the cognitive methodologies used have not allowed for disambiguation of two types of attentional biases. It remains unclear if PTSD involves difficulty disengaging attention from threatening stimuli (interference) or facilitated detection. To differentiate between attentional interference and facilitation, 57 male Vietnam-era veterans (30 High PTSD and 27 Low PTSD) completed a visual search task with a lexical decision component. High PTSD veterans who engaged in the interference task first showed increased interference to threat-relevant words relative to Low PTSD veterans. However, no evidence was found for facilitated detection of threatening stimuli in PTSD.     

Associations between childhood trauma and emotion-modulated psychophysiological responses to startling sounds: a study of police cadets

Childhood trauma may confer risk for adult psychopathology by altering emotional and physiological responses to subsequent stressors. Few studies have distinguished effects of childhood trauma from effects of current Axis I psychopathology on adult psychophysiological reactivity. The authors exposed 90 psychiatrically healthy police cadets to startling sounds under increasing threat of shock while assessing their eyeblink electromyogram (EMG), skin conductance (SC), and heart rate responses. When compared with those who did not endorse early trauma (n = 65), cadets reporting childhood trauma (n = 25) reported less positive emotion and showed greater SC responses across all threat levels. They also showed threat-dependent elevations in reported negative emotions and EMG responses. Results suggest that childhood trauma may lead to long-lasting alterations in emotional and psychophysiological reactivity even in the absence of current Axis I psychopathology.     

Resistance to Interference of Olfactory Perceptual Learning

The Psychological Record - Olfactory memory is especially persistent. The current study explored whether this applies to a form of perceptual learning, in which experience of an odor mixture...     

Visual category-selectivity for faces, places and objects emerges along different developmental trajectories

The organization of category-selective regions in ventral visual cortex is well characterized in human adults. We investigated a crucial, previously unaddressed, question about how this organization emerges developmentally. We contrasted the developmental trajectories for face-, object-, and place-selective activation in the ventral visual cortex in children, adolescents, and adults. Although children demonstrated adult-like organization in object- and place-related cortex, as a group they failed to show consistent face-selective activation in classical face regions. The lack of a consistent neural signature for faces was attributable to (1) reduced face-selectivity and extent of activation within the regions that will become the FFA, OFA, and STS in adults, and (2) smaller volumes and considerable variability in the locus of face-selective activation in individual children. In contrast, adolescents showed an adult-like pattern of face-selective activation, although it was more right-lateralized. These findings reveal critical age-related differences in the emergence of category-specific functional organization in the visual cortex and support a model of brain development in which specialization emerges from interactions between experience-dependent learning and the maturing brain.     

Preserved Implicit Knowledge of a Forgotten Childhood Language

ABSTRACT— Previous research suggests that a language learned during early childhood is completely forgotten when contact to that language is severed. In contrast with these findings, we report leftover traces of early language exposure in individuals in their adult years, despite a complete absence of explicit memory for the language. Specifically, native English individuals under age 40 selectively relearned subtle Hindi or Zulu sound contrasts that they once knew. However, individuals over 40 failed to show any relearning, and young control participants with no previous exposure to Hindi or Zulu showed no learning. This research highlights the lasting impact of early language experience in shaping speech perception, and the value of exposing children to foreign languages even if such exposure does not continue into adulthood.