Categorical and dimensional perceptions in decoding emotional facial expressions

We investigated whether categorical perception and dimensional perception can co-occur while decoding emotional facial expressions. In Experiment 1, facial continua with endpoints consisting of four basic emotions (i.e., happiness-fear and anger-disgust) were created by a morphing technique. Participants rated each facial stimulus using a categorical strategy and a dimensional strategy. The results show that the happiness-fear continuum was divided into two clusters based on valence, even when using the dimensional strategy. Moreover, the faces were arrayed in order of the physical changes within each cluster. In Experiment 2, we found a category boundary within other continua (i.e., surprise-sadness and excitement-disgust) with regard to the arousal and valence dimensions. These findings indicate that categorical perception and dimensional perception co-occurred when emotional facial expressions were rated using a dimensional strategy, suggesting a hybrid theory of categorical and dimensional accounts.     

Modification of depth and distance perception caused by long-term wearing of left-right reversing spectacles

For 35 to 39 days, four observers wore continuously left-right reversing spectacles which pseudoscopically reverse the order of binocular disparity and direction of convergence. In three tests, we investigated how the visual system copes with the transformation of depth and distance information due to the reversing spectacles. In stereogram observation, after a few days of wearing the spectacles. the observers sometimes perceived a depth order which was opposite to the depth order that they had perceived in the pre-spectacle-wearing period. Monocular depth cues contributed more to depth perception in the spectacle-wearing period than they did in the pre-spectacle-wearing period. While the perceived distance significantly decreased during the spectacle-wearing period, we found no evidence of adaptive change in distance perception. The results indicate that the visual system adapts itself to the transformed situation by not only changing the processing of disparity but also by changing the relative efficiency of each cue in determining apparent depth.     

Impact of On-Site Personal Experience of Violent Death on Posttraumatic Stress Disorder of Bereaved Japanese Family Members in Forensic Autopsy Cases

The present study investigated the influence of direct on-site experience of violent death on the symptoms involved in posttraumatic stress disorder (PTSD) of bereaved Japanese family members (n = 367) in forensic autopsy cases, using a questionnaire survey. Factor analyses of three core symptoms of PTSD confirmed the factor structure. In general linear modeling, the major effect of direct on-site experience of violent death on PTSD score was significant, while manner of death alone did not have such an effect. These findings suggest that direct on-site experience of violent death is essential in the clinical assessment of PTSD-related symptoms of bereaved family members.     

No Benefit of Eye-Closure Rehearsal in a Unimodal Recognition Memory Test for Word Items

Recent studies have suggested that closing the eyes helps memory retrieval in recall tests for audiovisual clips that contain multimodal information. In two experiments, we examined whether eye-closure improves recognition memory performance for word lists presented unimodally (i.e., visually or aurally). In the encoding phase, participants saw or heard a list of unrelated, meaningful word items. After a fixed retention interval of 1 week (Experiment 1, n = 110) and 5 min (Experiment 2, n = 44), the participants were asked to mentally rehearse the items with their eyes open or closed, and then they performed a recognition test. The results revealed no effect of eye-closure rehearsal on recognition performance. We discuss the possible reasons why no eye-closure benefit was found in recognition memory tests for unrelated word items.     

Information Seeking in a Non-Hypothesis Testing Task

The information gain model (Oaksford and Chater, Psychological Review 101, 608–631, 1994) advocates that participants attempt to achieve a larger expected information gain when they have to test an if-then rule or hypothesis. However, acquisition of larger expected information gain could also be operational when participants do not have to test a hypothesis. This study devised a new task to investigate whether participants would seek larger expected information gain when they were not required to test a hypothesis. The task required participants to select one out of two balance scales for weighing coins in order to detect an underweight coin. We discovered that participants more frequently selected the balance scale that provided smaller expected information gain. This finding suggests that the preference for larger expected information gain may not apply to non-hypothesis testing settings.