Recognizing faces in and out of context

Two experiments are reported which examined the influence of context on face recognition accuracy for novel and familiar faces respectively. Context was manipulated by varying the physical background against which the faces appeared. In Experiment I, 80 student subjects observed 18 faces before attempting to recognize them in a sequence of 36 alternatives. For half the subjects, the backgrounds changed from study to test, while for the remainder they stayed the same. In addition, for half the subjects, both the pose and expression of the face also changed, while for the others it remained constant. Changes in pose plus expression and context significantly reduced recognition accuracy for the target faces. Experiment II used an identical design, except that the faces of celebrities replaced the novel faces. The influence of context was eliminated but the effects of pose and expression were maintained. However, when only faces which were actually identified by subjects were considered, the effects of pose and expression, too, were eliminated. The significance of these findings for theories of contextual memory are discussed.     

Identification of familiar and unfamiliar faces from internal and external features: some implications for theories of face recognition

Three experiments are reported in which recognition of faces from whole faces or internal or external features was compared. In the first experiment, where the faces were of famous people, an advantage was found for identification from internal features. In the second experiment involving unfamiliar faces, however, no difference was found in recognition rates when subjects were given the internal or the external features. In a third experiment famous faces were presented and mixed with other famous faces for a recognition test. As in experiment 1, better recognition occurred from internals as compared with external features. It is argued that the internal representation for familiar faces may be qualitatively different from that for face seen just once. In particular some advantage in feature saliency may accrue to the internal or 'expressive' features of familiar faces. The implications of these results are considered in relation to general theories of face perception and recognition.     

Salt taste detection: an R-index approach to signal-detection measurements

The R-index approach to the signal-detection P(A) index of sensitivity was used to measure taste sensitivity to NaCl solutions. The R-index is the predicted probability of the correct choice of a signal, for a given signal-noise pair. For flow-wise and sipwise presentation, R-indices did not fluctuate significantly, provided subjects could not see the stimuli yet to be presented, indicating a lack of systematic sensitivity drift. The simultaneous measurement of more than one signal strength with reference to a common noise stimulus was seen to be a viable and sensitive procedure. Comparison of flow-wise and sipwise presentation of stimuli using R-indices, indicated that the former elicited greater subject sensitivity to NaCl taste.     

Brief Cognitive-Behavioral Therapy for Suicidal Inpatients

Suicide risk is elevated in psychiatric patients following discharge from inpatient care. Despite this vulnerability, there has been limited research investigating suicide prevention protocols that take into account the unique system characteristics of this setting (e.g., short lengths of stay, crisis stabilization treatment model, multidisciplinary team coordination). Cognitive-behavioral therapy (CBT) has demonstrated efficacy for improving suicide risk in outpatients, but has not been validated with inpatients. The current study was a treatment development and pilot feasibility open trial that modified brief cognitive-behavioral therapy (BCBT) for an inpatient setting (BCBT-I). Key treatment modifications included administering up to 10 sessions (depending on patient length of stay), daily, and in a standardized order, with core crisis management skills introduced during the first three sessions. In addition, coordination with the inpatient treatment team was included in BCBT-I implementation. Six adult inpatients with a recent suicide attempt enrolled and completed an average of 4.67 BCBT-I sessions (SD = 1.36). The treatment was highly acceptable (Client Satisfaction Questionnaire total score M = 3.49, SD = 0.73). Pre- to posttreatment effect sizes demonstrated improvements in suicidal ideation (d = 0.97), depression (d = 1.33), and suicidal implicit associations (d = 1.28). All but one of the participants (83%) completed follow-up assessments 1-, 2-, and 3-months postdischarge. Over follow-up, two participants reported suicidal ideation (both without intent), and none reported suicide attempts, preparatory acts or behaviors, or nonsuicidal self-injury. This study provided preliminary evidence supporting the feasibility of CBT to treat suicidal inpatients. Future research is needed to validate BCBT-I in a larger, randomized controlled trial to determine whether BCBT-I reduces suicide risk beyond that afforded by inpatient treatment alone.     

Action representation deficits in adolescents with developmental dyslexia

Developmental dyslexia (DD), a severe and frequent disorder of reading acquisition, is characterized by a diversity of cognitive and motor deficits whose interactions still remain under debate. Although deficits in the automatization of sensorimotor control have been highlighted, internal action representation allowing prediction has never before been investigated. In this study, we considered action representation of 18 adolescents with pure DD and 18 age-matched typical readers. Participants actually and mentally performed a visually guided pointing task involving strong spatiotemporal constraints (speed/accuracy trade-off paradigm). While actual and mental movement times of typical readers were isochronous and both conformed to Fitts’ law, the movement times of dyslexics differed between conditions, and only the actual movement times conformed to Fitts’ law. Furthermore, the quality of motor imagery correlated with word reading abilities. This suggests that the process of action representation is impaired in pure DD and supports the sensorimotor perspective of DD. Theoretical implications are discussed.     

Adults with dyslexia demonstrate space-based and object-based covert attention deficits: shifting attention to the periphery and shifting attention between objects in the left visual field

Performance on a covert visual attention task is compared between a group of adults with developmental dyslexia (specifically phonological difficulties) and a group of age and IQ matched controls. The group with dyslexia were generally slower to detect validly-cued targets. Costs of shifting attention toward the periphery when the target was invalidly cued were significantly higher for the group with dyslexia, while costs associated with shifts toward the fovea tended to be lower. Higher costs were also shown by the group with dyslexia for up-down shifts of attention in the periphery. A visual field processing difference was found, in that the group with dyslexia showed higher costs associated with shifting attention between objects in they LVF. These findings indicate that these adults with dyslexia have difficulty in both the space-based and the object-based components of covert visual attention, and more specifically to stimuli located in the periphery.