Symbolic- and response-related contributions to blindness to compatible stimuli

Blindness to compatible stimuli refers to poorer target identification (e.g., right-pointing arrowhead) following compatible stimuli (e.g., right arrows; Stevanovski, Oriet, & Jolic?ur, 2003) and compatible responses (e.g., right key press; Müsseler & Hommel, 1997a and 1997b). To clarify the role of the response in this effect, we examined the impact of adding or removing an overt response. In three experiments, subjects saw an arrow cue (that sometimes required a response) followed by a brief, masked arrowhead, which was reported on all trials. In all experiments, making a response increased the magnitude of the blindness effect. Furthermore, “no response” performance was unaffected by whether subjects had previously responded to the cue. Results favour a two-factor symbolic- plus response-related activation model over a purely symbolic activation model.     

The whole is indeed more than the sum of its parts: perceptual averaging in the absence of individual item representation

We tested Ariely's (2001) proposal that the visual system represents the overall statistical properties of sets of objects against alternative accounts of rapid averaging involving sub-sampling strategies. In four experiments, observers could rapidly extract the mean size of a set of circles presented in an RSVP sequence, but could not reliably identify individual members. Experiment 1 contrasted performance on a member identification task with performance on a mean judgment task, and showed that the tasks could be dissociated based on whether the test probe was presented before or after the sequence, suggesting that member identification and mean judgment are subserved by different mechanisms. In Experiment 2, we confirmed that when given a choice between a probe corresponding to the mean size of the set and a foil corresponding to the mean of the smallest and largest items only, the former is preferred to the latter, even when observers are explicitly instructed to average only the smallest and largest items. Experiment 3 showed that a test item corresponding to the mean size of the set could be reliably discriminated from a foil but the largest item in the set, differing by an equivalent amount, could not. In Experiment 4, observers rejected test items dissimilar to the mean size of the set in a member identification task, favoring test items that corresponded to the mean of the set over items that were actually shown. These findings suggest that mean representation is accomplished without explicitly encoding individual items.     

It's in the sample: the effects of sample size and sample diversity on the breadth of inductive generalization

Developmental studies have provided mixed evidence with regard to the question of whether children consider sample size and sample diversity in their inductive generalizations. Results from four experiments with 105 undergraduates, 105 school-age children (M = 7.2 years), and 105 preschoolers (M = 4.9 years) showed that preschoolers made a higher rate of projections from large samples than from small samples when samples were diverse (Experiments 1 and 3) but not when samples were homogeneous (Experiment 4) and not when the task required a choice between two samples (Experiment 2). Furthermore, when a property occurred in large and diverse samples, preschoolers exhibited a broad pattern of projection, generalizing the property to items from categories not represented in the evidence. In contrast, adults followed a normative pattern of induction and never attributed properties to items from categories not represented in the evidence. School-age children showed a mixed pattern of results.     

Differentiating Bipolar Disorder from Major Depressive Disorder Using the MMPI-2-RF: A Receiver Operating Characteristics (ROC) Analysis

We examined the utility of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) to differentiate patients with lifetime bipolar disorder (BD) from patients with lifetime major depressive disorder (MDD), and to differentiate patients with BD who are currently depressed from patients with current MDD. Sixty-one patients with BD (BD-I n = 51, BD-II n = 10) and 381 patients with MDD were administered the MMPI-2; MMPI-2-RF scale scores were derived from these MMPI-2 protocols. Receiver operating characteristics analysis revealed that the MMPI-2-RF Activation (ACT) scale had the largest Area Under the Curve (AUC), which was 0.74. Using a cut-off score of 4 on the ACT scale resulted in 71% of patients being correctly classified as having BD or MDD (sensitivity = 0.67, specificity = 0.71). An examination of currently depressed patients with BD (n = 29) and a randomly selected sample of MDD patients (n = 29) revealed that the ACT scale correctly classified 72% of patients (AUC = 0.75, sensitivity = 0.69, specificity = 0.76). Implications and limitations of these findings were discussed.     

A search asymmetry for interocular conflict

When two different images are presented to the two eyes, the percept will alternate between the images (a phenomenon called binocular rivalry). In the present study, we investigate the degree to which such interocular conflict is conspicuous. By using a visual search task, we show that search for interocular conflict is near efficient (15 ms/item) and can lead to a search asymmetry, depending on the contrast in the display. We reconcile our findings with those of Wolfe and Franzel (1988), who reported inefficient search for interocular conflict (26 ms/item) and found no evidence for a search asymmetry. In addition, we provide evidence for the suggestion that differences in search for interocular conflict are contingent on the degree of abnormal fusion of the dissimilar images.     

Aping expressions? Chimpanzees produce distinct laugh types when responding to laughter of others

Humans have the ability to replicate the emotional expressions of others even when they undergo different emotions. Such distinct responses of expressions, especially positive expressions, play a central role in everyday social communication of humans and may give the responding individuals important advantages in cooperation and communication. The present work examined laughter in chimpanzees to test whether nonhuman primates also use their expressions in such distinct ways. The approach was first to examine the form and occurrence of laugh replications (laughter after the laughter of others) and spontaneous laughter of chimpanzees during social play and then to test whether their laugh replications represented laugh-elicited laugh responses (laughter triggered by the laughter of others) by using a quantitative method designed to measure responses in natural social settings. The results of this study indicated that chimpanzees produce laugh-elicited laughter that is distinct in form and occurrence from their spontaneous laughter. These findings provide the first empirical evidence that nonhuman primates have the ability to replicate the expressions of others by producing expressions that differ in their underlying emotions and social implications. The data further showed that the laugh-elicited laugh responses of the subjects were closely linked to play maintenance, suggesting that chimpanzees might gain important cooperative and communicative advantages by responding with laughter to the laughter of their social partners. Notably, some chimpanzee groups of this study responded more with laughter than others, an outcome that provides empirical support of a socialization of expressions in great apes similar to that of humans.     

Acoustic correlates of emotional dimensions in laughter: arousal, dominance, and valence

Although laughter plays an essential part in emotional vocal communication, little is known about the acoustical correlates that encode different emotional dimensions. In this study we examined the acoustical structure of laughter sounds differing along four emotional dimensions: arousal, dominance, sender's valence, and receiver-directed valence. Correlation of 43 acoustic parameters with individual emotional dimensions revealed that each emotional dimension was associated with a number of vocal cues. Common patterns of cues were found with emotional expression in speech, supporting the hypothesis of a common underlying mechanism for the vocal expression of emotions.     

How Sensation Seeking provides a common basis for functional and dysfunctional outcomes

This research determines if Mastery Goal Orientation mediates Sensation Seeking in the prediction of functional performance and if Sensation Seeking directly predicts dysfunctional behavior. Using two different measures of Sensation Seeking, a sample of fulltime Australian workers was used to test the proposed learning mechanism in the prediction of supervisor rated work outcomes, self-reported work outcomes, and self-reported dysfunctional behavior. As predicted, mediation and suppression analyses provided strong support for the proposed model but with just one of the measures of Sensation Seeking. It is concluded that this mechanism of learning has much to offer our understanding of functional and dysfunctional outcomes.     

Hearing speech in noise: seeing a loud talker is better

Seeing the talker improves the intelligibility of speech degraded by noise (a visual speech benefit). Given that talkers exaggerate spoken articulation in noise, this set of two experiments examined whether the visual speech benefit was greater for speech produced in noise than in quiet. We first examined the extent to which spoken articulation was exaggerated in noise by measuring the motion of face markers as four people uttered 10 sentences either in quiet or in babble-speech noise (these renditions were also filmed). The tracking results showed that articulated motion in speech produced in noise was greater than that produced in quiet and was more highly correlated with speech acoustics. Speech intelligibility was tested in a second experiment using a speech-perception-in-noise task under auditory-visual and auditory-only conditions. The results showed that the visual speech benefit was greater for speech recorded in noise than for speech recorded in quiet. Furthermore, the amount of articulatory movement was related to performance on the perception task, indicating that the enhanced gestures made when speaking in noise function to make speech more intelligible.     

Timing of reflexive visuospatial orienting in young, young-old, and old-old adults

This study examined adult age differences in reflexive orienting to two types of uninformative spatial cues: central arrows and peripheral onsets. In two experiments using a Posner cuing task, young adults (ages 18–28 years), young-old adults (60–74 years), and old-old adults (75–92 years) responded to targets that were preceded 100–1,000 ms earlier by a central arrow or a peripheral abrupt onset. In Experiment 1, the cue remained present upon target onset. Facilitation effects at short cue–target stimulus onset asynchronies (SOAs) were prolonged in duration for the two older groups relative to the young adults. At longer cue–target SOAs, inhibition of return (IOR) that was initiated by peripheral onset cues was observed in the performance of young adults but not in that of the two older groups. In Experiment 2, the cue was presented briefly and removed prior to target onset. The change in cue duration minimized age differences (particularly for young-old adults) in facilitation effects and led to IOR for all three age groups. The findings are consistent with the idea that attentional control settings change with age, with higher settings for older adults leading to delayed disengagement from spatial cues.