Reafference learning in the presence of exafference

Reafference learning has been demonstrated most clearly in the case of position-constancy adaptation in which the only stimulus change is caused by the subject’s own movoment. The present study used the more ecologically representative training situation in which only part of the stimulus change is caused by the subject (reafference), while part of it is caused by an independent source (exafference). The exafference varied the space relation between subject movement and optical movement or the time relation between those two. In both cases, reafference learning was not affected by the exafference, and the subject’s varied training experience resulted in a fixed expected optical movement and a fixed expected time lag.     

Position constancy and binocular convergence

The position constancy during head movement of a luminous spot in a dark room depends in part on the convergence state of the eyes. This supports a modified form of the theory that an optical-motion/head-motion comparator contributes to constancy. By incorporating convergence information, the comparator can allow [or the effect of parallax on the optical-motion/body-motion ratio.     

Familiarity decisions for faces presented to the left and right cerebral hemispheres

Right-handed subjects were asked to decide whether or not faces presented briefly in the RVF or in the LVF were familiar (familiar faces were those of famous people). This task avoids the need for extensive semantic processing or temporary storage involved in conventional naming or identification tasks, and thus eliminates the contribution of such factors to any observed asymmetry. The resulting finding of faster reaction times to LVF faces, with no overall visual hemifield difference in error rates, is taken to indicate a right-hemisphere superiority either in the processes used to construct facial representations or in the accessing of face recognition units, or both.     

Distinctiveness,typicality, and recollective experience in face recognition: A principal components analysis

In this study, participants rated previously unseen faces on six dimensions: familiarity, distinctiveness, attractiveness, memorability, typicality, and resemblance to a familiar person. The faces were then presented again in a recognition test in which participants assigned their positive recognition decisions to either remember (R), know (K), or guess categories. On all dimensions except typicality, faces that were categorized as R responses were associated with significantly higher ratings than were faces categorized as K responses. Study ratings for R and K responses were then subjected to a principal components analysis. The factor loadings suggested that R responses were influenced primarily by the distinctiveness of faces, but K responses were influenced by moderate ratings on all six dimensions. These findings indicate that the structural features of a face influence the subjective experience of recognition.     

Repetition priming of face gender judgments: An instance based explanation

Earlier studies of repetition priming using faces have been interpreted as indicating that such effects are confined to the processing of known faces. The experiment reported here employed eight rather than the more usual two presentation trials and required subjects to make gender decisions (is it a male or is it a female face?) to both familiar and unfamiliar faces. This allowed the currently favored recognition unit theories of face processing to be compared with the Logan (1988) instance model. Equivalent repetition priming effects were observed for both familiar and unfamiliar faces and were well fitted by power functions. It is argued that the findings are consistent with the strong predictions made by Logan's model and pose problems for recognition unit based theories.     

Repetition priming of face gender judgments: An instance based explanation

Earlier studies of repetition priming using faces have been interpreted as indicating that such effects are confined to the processing of known faces. The experiment reported here employed eight rather than the more usual two presentation trials and required subjects to make gender decisions (is it a male or is it a female face?) to both familiar and unfamiliar faces. This allowed the currently favored recognition unit theories of face processing to be compared with the Logan (1988) instance model. Equivalent repetition priming effects were observed for both familiar and unfamiliar faces and were well fitted by power functions. It is argued that the findings are consistent with the strong predictions made by Logan's model and pose problems for recognition unit based theories.     

Sex differences in genetic and environmental influences on DSM-III-R attention-deficit/hyperactivity disorder

Approximately 5% of children are affected by attention-deficit/hyperactivity disorder (ADHD), and more boys are affected than girls. This study examined the magnitude of genetic and environmental influences on ADHD and several questions regarding sex differences in its prevalence and liability. The participants were 2,391 twin and sibling pairs from Australia, ages 3-18. ADHD symptoms in the general population were highly heritable (h2 = .85-.90), as were deviant ADHD scores in the selected population. The magnitude of familial influences was similar for boys and girls, although there were shared environmental influences on ADHD in girls but not boys and dominance genetic influences on ADHD in boys but not girls. Specific genetic and environmental influences were highly similar for boys and girls. Evidence supported the polygenic multiple threshold model rather than the constitutional variability model of sex differences in ADHD.     

Aging and judgments of duration: Effects of task complexity and method of estimation

The effects of aging on judgments of short temporal durations were explored using the prospective paradigm and the methods of verbal estimation and production. Younger and older adults performed a perceptual judgment task at five levels of complexity for periods of 30, 60, and 120 sec. Participants either continued to perform the task for a specified interval (production) or were stopped and then verbally estimated the interval. Older adults gave shorter verbal estimates and longer productions than did younger adults. The methods of verbal estimation and production yielded approximately equal duration judgment ratios once range effects were taken into account. Task complexity had little effect. The major conclusion is that duration judgment ratios decrease from younger to older adults when the intervals are filled with a mental task.     

Couples treatment of agoraphobia: changes in marital satisfaction

Six agoraphobic women and their husbands participated in a group therapy program consisting of exposure and cognitive restructuring. The husbands acted as co-therapists. Ratings of marital satisfaction as well as severity of phobia were filled out independently by both clients and their husbands throughout the course of therapy and at follow-up. Two patterns of relationships among marital satisfaction and severity of phobia emerged. For four couples a parallel relationship was observed in that as phobia improved marital satisfaction increased. For two couples the inverse relationship was noted where improvements in phobia were correlated with decreases in marital satisfaction. The importance of the interpersonal context of agoraphobia and implications for treatment are suggested.     

Eating Disorder Examination Questionnaire (EDE-Q): norms for young adult women

In order to establish norms for the Eating Disorder Examination Questionnaire (EDE-Q) among young adult women, the questionnaire was administered to a large general population sample of women aged 18-42 yr in the Australian Capital Territory (ACT) region of Australia. Normative data were derived for EDE-Q subscales and for the occurrence of specific eating disorder behaviours, for each of five age bands (18-22, 23-27, 28-32, 33-37, 38-42 yr). Mean scores (SDs) for the Restraint, Eating Concern, Weight Concern and Shape Concern subscales for the total sample (n = 5,255) were, respectively, 1.30 (1.40), 0.76 (1.06), 1.79 (1.51) and 2.23 (1.65). The mean global score was 1.52 (1.25). The regular occurrence of objective and subjective overeating episodes was reported by 10.6% and 12.7% of participants, respectively. The regular use of self-induced vomiting, laxative misuse, and use of diuretics, was reported by 1.4%, 1.0%, and 0.3%, of participants, respectively, while 2.2% of participants reported regularly using diet pills. "Extreme dietary restraint" and "excessive exercise" were reported by 3.4% and 4.9% of participants, respectively. Both attitudinal and behavioural features of eating disorder psychopathology tended to decrease with increasing age. These data will inform researchers intending to use the EDE-Q in epidemiological studies.