On the relations between implicit and explicit spatial binding: Evidence from Balint’s syndrome

We report two experiments examining whether factors that affect binding in explicit report tasks also affect implicit binding in a patient with Balint’s syndrome, G.K. Replicating prior studies, we showed that there could be implicit binding of visual features in a patient with Balint’s syndrome who was at chance at explicitly discriminating the relations between the features. Nevertheless, when color—form relationships were coded, we showed that G.K.’s implicit binding, as well as his explicit report of binding relationships, was affected by the spatial distance between the stimuli. Similarly, we demonstrated effects of grouping on both implicit and explicit binding of the spatial relations between shapes. We interpret the qualitative similarities between implicit and explicit binding as indicating that they reflect a single process in which binding relations, initially established preattentively, are later consolidated by attention. This later process, of attentional consolidation, is disrupted in Balint’s syndrome.     

What do we know about psycholinguistic effects?

Identifying clear and unequivocal psycholinguistic effects for lexical retrieval tasks has been the aim of a significant proportion of recent research activity. Debates have erupted concerning the existence or otherwise of particular effects on particular lexical tasks. Here, it is suggested that the reason for these debates is that researchers exercise choice in what variables they consider in their analysis. It is further illustrated that methods that have been employed for comparing the size of these effects between tasks can only lead to inconclusive results. It is suggested that psycholinguistic data may be better analysed using structural equation modelling methodologies. An example of such an approach is presented.     

Adults' ability to detect children's lying

Adults are poor deception detectors when examining lies told by adults, on average. However, there are some adults who are better at detecting lies than others. Children learn to lie at a very young age, a behavior that is socialized by parents. Yet, less is known about the ability to detect children's lies, particularly with regard to individual differences in the ability to detect this deception. The current study explored adult raters' ability to discern honesty in children who lied or told the truth about committing a misdeed. Results showed that adults are no better at detecting children's lies than they are with adult lies. In particular, adults were very poor at identifying children's honest statements. However, individual differences did emerge, suggesting that the ability to detect lying in children might be facilitated by relevant experience working with children. Implications for legal and mental health contexts are discussed.     

Is it impossible to inhibit isoluminant items, or does it simply take longer? Evidence from preview search

Visual search can be facilitated when participants receive a preview of half the distractors (the preview benefit in search; Watson & Humphreys, 1997). Donk and Theeuwes (2001) have argued that preview-based benefits are abolished if the display items are isoluminant to a background. This is consistent with the preview benefit being due to onset capture by the new stimuli. In contrast, the present experiments challenge this suggestion and show that preview benefits can occur under isoluminant conditions, providing that they are given enough time to occur. In Experiment 1, we showed that a preview benefit can occur even with isoluminant stimuli, provided that the old items are previewed for a sufficient time. In Experiment 2, we tested and rejected the idea that this advantage is due to low-level sensory fatigue for the preview stimuli. These findings indicate that the preview effect is not caused solely by onset capture.     

Object-based inhibitory priming in preview search: Evidence from the “top-up” procedure

Visual search in a conjunction task can be facilitated if half the distractor items are previewed prior to the other half of the distractors and the target item. Here, we investigate the nature of this preview by using a top-up procedure, which presents an initial preview followed by a secondary preview after a period of time (the offset period). In Experiment 1, we demonstrate that increasing the time of the offset period decreases search efficiency. If the offset period is increased to 2 sec, the previewed items are searched to a greater extent than when the offset period is 450 msec. This holds even when the old items remain in the same positions across presentations and when they differ in color from new search stimuli. However, when the offset intervals are reduced, the preview can be discounted from search even when the old items change locations between exposures (Experiment 2) and when they are not distinguished from search displays by their color (Experiment 3). The last result occurs only as long as the preview items can be grouped in terms of form. When the preview stimuli are heterogeneous, they are no longer discounted from search if their locations change across the offset period (Experiment 4). We interpret the data in terms of object-based priming, which enables the repeated form of the old distractors to be filtered more easily from search.     

Examination stress as an ecological inducer of cortisol and psychological responses to stress in undergraduate students

The purpose of the present study was to investigate basic methodological issues related to the usage of an examination stress protocol in studies of psychoneuroendocrinology. In the present study, 57 undergraduate students served as participants. All subjects provided salivary samples and completed psychological inventories during a low examination stress period and again during a high examination stress period. Salivary samples were analyzed for cortisol. Three major findings were observed. First, the examination stress protocol proved to be an effective trigger of elevations in both psychological measures of stress and in cortisol levels. Second, sex differences were observed in cortisol levels, such that males showed an elevation in cortisol during the high examination stress session whereas females did not. Finally, no significant correlations were observed between elevations in psychological measures of stress and elevations in cortisol levels. These findings suggest that the examination stress protocol used in the present study effectively elevated both psychological stress and cortisol levels. Furthermore, these findings suggest that there are biological differences in how males and females respond to stress. Finally, no evidence was found to suggest a relationship between psychological and hormonal levels of stress. Together, these findings suggest the need to better define and consider the implications of both the specific measures of stress being used and individual differences in the subject samples in psychoendocrine studies.     

Sustained vs. transient cognitive control: Evidence of a behavioral dissociation

This study assessed whether two well known effects associated with cognitive control, conflict adaptation (the Gratton effect) and conflict context (proportion congruent effects), reflect a single common or separate control systems. To test this we examined if these two effects generalized from one kind of conflict to another by using a combined-conflict paradigm (involving the Simon and Spatial Stroop tasks) and manipulating the proportion of congruent to incongruent trials for one conflict (Simon) but not the other (Spatial Stroop). We found that conflict adaptation effects did not generalize, but the effect of conflict context did. This contrasting pattern of results strongly suggests the existence of two separate attentional control systems, one transient and responsible of online regulation of performance (conflict adaptation), the other sustained and responsible for conflict context effects.