Information transmission for one-dimensional stimuli: The role of strategies

Important evidence about the information flow between perceptual and motor processes has been obtained from the lateralized readiness potential (LRP) recorded in two-choice go/nogo tasks. Here, we investigated the effect of time pressure on information transmission for one-dimensional stimuli (four squares differing in size). In between- and within-subject designs, respectively, Experiments 1 and 2 showed that under time pressure partial information initiates hand decision and response preparation before complete size information is available. These findings appear to be at odds with the asynchronous discrete coding model. Experiment 3 assessed the mechanisms behind these effects by manipulating the relative difficulty of extracting hand- and go/nogo-specific information from the size of the stimuli. Consistent with asynchronous coding, our results suggest that serial-consecutive processes in extracting partial and full size information may occur also for one-dimensional stimuli. Our data are inconclusive as to the question of discreteness or continuity of information transmission. On a more general level, our data support the notion of flexibility in the coding of perceptual dimensions to adapt performance to environmental conditions.     

Personality Traits in Clinical Depression and Remitted Depression: An Analysis of Instrumental-Agentic and Expressive-Communal Traits

The present study evaluated levels of instrumental and expressive traits and vulnerability to severe depression. A sample of 44 depressed psychiatric patients (i.e., 22 currently depressed patients and 22 remitted depressed patients) completed the Beck Depression Inventory and the Personal Attributes Questionnaire, a well-known personality measure that assesses masculinity (i.e., instrumentality) and femininity (i.e., expressivity). Analyses revealed that currently depressed patients, relative to the remitted depressed patients, had significantly lower levels of both instrumental and expressive traits. Overall, most currently depressed patients were characterized by unhealthy, undifferentiated sex-role self-concepts (i.e., low levels of masculinity and femininity) while the sex-role self-concepts of remitted depressed patients closely resembled those found in nonclinical populations. The current results qualify recent research on the impact of depression on personality ratings by suggesting that severe depression may contribute by lowering scores on self-report assessments of socially desirable personality traits reflecting agentic, instrumental characteristics, and communal, expressive characteristics.     

Adult age differences in inhibitory processes and their predictive validity for fluid intelligence

According to the inhibition-deficit hypothesis age differences in working memory capacity and fluid intelligence have been attributed to a decline in inhibitory efficiency. Conceptualizing inhibition as multifaceted, 88 participants (49 younger and 39 elderly) completed two versions of the negative priming paradigm (identification and localization), and two variants of the directed forgetting paradigm (listwise and itemwise). Two tasks of the Wechsler Intelligence Test with high loadings on general fluid intelligence (Gf) served as validation criteria. Results revealed task-specific and speed-independent inhibitory deficits in the elderly (lower negative priming in both paradigms; more intrusions in the directed forgetting tasks), as well as higher levels of repetition priming. Significant correlations between measures of inhibition and the Wechsler scores were found in both age groups. Results support the view of multiple inhibitory-like capabilities that play a central role in the decline of higher-order cognitive functions in old age.     

Recognition of affective prosody in brain-damaged patients and healthy controls: A neurophysiological study using EEG and whole-head MEG

A passive oddball experiment was used in which stimuli were emotional exclamations differing in their affective tone. In both electroencephalography (EEG) and magnetoencephalography (MEG), deviants elicited an N300 component, sometimes accompanied by a slow wave. Both components had a symmetrical distribution, but the former was more posterior than the latter. The same responses to prosodic stimuli were significant in 6 of 27 patients with severe disorders of consciousness (persistent vegetative state and minimally conscious state) and in all 3 of the examined locked-in patients, indicating that the procedure can be applied for testing neurological patients. The occurrence of significant responses depended on the presence or absence of a lesion to the right temporal lobe. Obviously, the N300 depends on the activity of the right temporal cortex but does not originate there. We suggest that the component is related not to the recognition of affective prosody as such, but to the following detection of affective mismatch due to violations of emotional context of stimulation.     

Preceding stimulus awareness augments offset-evoked potentials: Evidence from motion-induced blindness

Event-related potentials (ERPs) were measured in response to the objective offset of a visual disk under two physically similar conditions: (1) visible conditions in which the target disk was well perceived and (2) invisible conditions in which participants reported to have not seen the target because of motion-induced blindness (Bonneh, Cooperman, & Sagi in Nature 411:798-801, 2001). Electrophysiological responses to the physical offset of the target disk were almost completely absent in the invisible conditions (Experiment 2). In the same conditions, the physical offset was almost completely invisible (Experiment 1). Results suggest an augmenting function of prior awareness of a stimulus for the offset-triggered ERP of that stimulus.     

Individual differences in components of reaction time distributions and their relations to working memory and intelligence

The authors bring together approaches from cognitive and individual differences psychology to model characteristics of reaction time distributions beyond measures of central tendency. Ex-Gaussian distributions and a diffusion model approach are used to describe individuals' reaction time data. The authors identified common latent factors for each of the 3 ex-Gaussian parameters and for 3 parameters central to the diffusion model using structural equation modeling for a battery of choice reaction tasks. These factors had differential relations to criterion constructs. Parameters reflecting the tail of the distribution (i.e., tau in the ex-Gaussian and drift rate in the diffusion model) were the strongest unique predictors of working memory, reasoning, and psychometric speed. Theories of controlled attention and binding are discussed as potential theoretical explanations.     

Post-training reversible inactivation of the rat's basolateral amygdala interferes with hippocampus-dependent place avoidance memory in a time-dependent manner

In this study, tetrodotoxin (TTX) inactivation was employed to evaluate the involvement of the rat's basolateral amygdala (BLA) in hippocampus-dependent spatial memory using a place avoidance learning task. Rats were trained in single 30 min session to avoid a 60 degrees segment of the stable circular (80-cm diameter) arena, entering which was punished by a mild shock. Bilateral injections of TTX or saline were made either immediately, 1 or 2h after training. Retention was tested 24h later in a 30 min extinction session. Retention was impaired when both BLA inactivated immediately or 1h after training, but not 2h after training. These data indicate that activity in the BLA, at least 60 min after training, is necessary for the post-training processing of a hippocampus-dependent place avoidance memory.     

Vibration-Induced Kinesthetic Illusions and Corticospinal Excitability Changes

The authors' aim was to investigate the changes of corticospinal excitability during kinesthetic illusions induced by tendon vibration. Motor-evoked potentials in response to transcranial magnetic stimulation were recorded from the vibrated flexor carpi radialis and its antagonist, extensor carpi radialis. The illusions were evoked under vision conditions without feedback for the position of the wrist (open or closed eyes). In these two conditions motor-evoked potential changes during vibration in the antagonist were not identical. This discrepancy may be a result of 2 simultaneously acting, different and opposite influences and the balance between them depends on visual conditions. Thus, the illusion was accompanied by the facilitation of corticospinal excitability in both vibrated muscle and its antagonist.     

A Posteriori Ethical Intuitionism and the Problem of Cognitive Penetrability

According to a posteriori ethical intuitionism (AEI), perceptual experiences can provide non‐inferential justification for at least some moral beliefs. Moral epistemology, for the defender of AEI, is less like the epistemology of math and more like the epistemology of tables and chairs. One serious threat to AEI comes from the phenomenon of cognitive penetration. The worry is that even if evaluative properties could figure in the contents of experience, they would only be able to do so if prior cognitive states influence perceptual experience. Such influences would undermine the non‐inferential, foundationalist credentials of AEI. In this paper, I defend AEI against this objection. Rather than deny that cognitive penetration exists, I argue that some types of cognitive penetrability are actually compatible with AEI's foundationalist structure. This involves teasing apart the question of whether some particular perceptual process has justification‐conferring features from the question of how it came to have those features in the first place. Once this distinction is made, it becomes clear that some kinds of cognitive penetration are compatible with the non‐inferential status of moral perceptual experiences as the proponent of AEI claims.