A Type Reduction from Proof-conditional to Dynamic Semantics

Dynamic and proof-conditional approaches to discourse (exemplified by Discourse Representation Theory and Type-Theoretical Grammar, respectively) are related through translations and transitions labeled by first-order formulas with anaphoric twists. Type-theoretic contexts are defined relative to a signature and instantiated model-theoretically, subject to change.     

How do we process prices? Electrophysiological evidence of componential analysis

The aim of this study was to evaluate if the processing of prices (e.g., 8 euro) involves separate analysis of the digit (8) and the monetary category (euro). Event-related potentials (ERPs) were recorded when participants performed a price comparison task in which a pair of prices was presented and they selected the one with higher monetary value. There were compatible comparisons where the digit and the monetary category of one price were higher than those of the other price (e.g., 7 euro – 4 cent, 7 > 4 and euro > cent), and incompatible comparisons where the number of one price was larger but the monetary category smaller than those of the other price (e.g., 4 euro – 7 cent, 4 < 7 but euro > cent). Compatibility effect modulated ERPs in the 350–450 ms time window, with more negative amplitudes in incompatible trials relative to compatible trials. This pattern of results suggests that prices were processed in a componential manner, challenging the evidences of the holistic model. The results of this study agree with the general model framework for multi-symbol number comparison: The constituents of a multi-symbol magnitude are processed and compared to each other separately in a componential manner.     

Aphasic naming in Spanish: predictors and errors

Sixteen Spanish aphasic patients named drawings of objects on three occasions. Multiple regression analyses were carried out on the naming accuracy scores. For the patient group as a whole, naming was affected by visual complexity, object familiarity, age of acquisition, and word frequency. The combination of variables predicted naming accuracy in 15 of the 16 individual patients. Age of acquisition, word frequency, and object familiarity predicted performance in the greatest number of patients, while visual complexity, imageability, animacy, and length all affected performance in at least two patients. High proportions of semantic and phonological errors to particular objects were associated with objects having early learned names while high proportions of no-response errors were associated with low familiarity and low visual complexity. It is suggested that visual complexity and object familiarity affect the ease of object recognition while word frequency affects name retrieval. Age of acquisition may affect both stages, accounting for its influence in patients with a range of different patterns of disorder.     

Computerized stroop test to assess selective attention in children with attention deficit hyperactivity disorder

Research shows abnormal function of the pre-frontal cortex in Attention Deficit Hyperactivity Disorder (ADHD). This cortex is involved in the control of executive functions related to planning and execution of goal-oriented strategies, working memory, inhibitions, cognitive flexibility, and selective attention. Selective attention involves focus on the target stimulus, ignoring competing distractions. The Stroop Test (Stroop, 1935) is usually used to evaluate selective attention. This study investigated whether children with ADHD could exhibit modified performance in the Stroop Test. Using a computerized version of this test (Capovilla, Montiel, Macedo, & Charin, 2005), the study compared the reaction times (RTs) of 62 Brazilian children, between 8 and 12 years of age, 31 of whom were diagnosed with ADHD and sent to psychiatric clinics, and 31 without ADHD studying in regular schools. All children with ADHD satisfied the criteria of the DSM-IV-TR and were evaluated with the Conners Abbreviated Questionnaire (Goyette, Conners, & Ulrich, 1978), completed by parents and teachers. The results revealed that children with ADHD exhibit greater interference in RT than children without ADHD. This corroborated the hypothesis that children with ADHD exhibit a deficit in selective attention, consisting in augmented RTs, as measured by the Computerized Stroop Test.     

The relation of white matter hyperintensities to cognitive performance in the normal old: education matters

This study examined whether the severity of cerebral white matter abnormalities (evident on MR images as white matter hyperintensities (WMH)) was related to the cognitive performance of 141 high-functioning older adults. The elderly showed the typical age decrement on measures of processing speed, working memory, and inhibition; however WMH severity was significantly related only to processing speed. The strength of this relationship was, however, influenced by the educational level of the participants, such that processing speed was more associated with WMH severity in less-educated than in well-educated participants. This is consistent with recent concepts of cognitive reserve, but does raise a question as to the underlying source of the cognitive decrement found in the sort of well-educated elders typically used in cognitive-aging studies.     

From Blickets to Synapses: Inferring Temporal Causal Networks by Observation

How do human infants learn the causal dependencies between events? Evidence suggests that this remarkable feat can be achieved by observation of only a handful of examples. Many computational models have been produced to explain how infants perform causal inference without explicit teaching about statistics or the scientific method. Here, we propose a spiking neuronal network implementation that can be entrained to form a dynamical model of the temporal and causal relationships between events that it observes. The network uses spike‐time dependent plasticity, long‐term depression, and heterosynaptic competition rules to implement Rescorla–Wagner‐like learning. Transmission delays between neurons allow the network to learn a forward model of the temporal relationships between events. Within this framework, biologically realistic synaptic plasticity rules account for well‐known behavioral data regarding cognitive causal assumptions such as backwards blocking and screening‐off. These models can then be run as emulators for state inference. Furthermore, this mechanism is capable of copying synaptic connectivity patterns between neuronal networks by observing the spontaneous spike activity from the neuronal circuit that is to be copied, and it thereby provides a powerful method for transmission of circuit functionality between brain regions.     

Making the uncontrollable seem controllable: the role of action in the illusion of control

It is well known that certain variables can bias judgements about the perceived contingency between an action and an outcome, making them depart from the normative predictions. For instance, previous studies have proven that the activity level or probability of responding, P(R), is a crucial variable that can affect these judgements in objectively noncontingent situations. A possible account for the P(R) effect is based on the differential exposure to actual contingencies during the training phase, which is in turn presumably produced by individual differences in participants' P(R). The current two experiments replicate the P(R) effect in a free-response paradigm, and show that participants' judgements are better predicted by P(R) than by the actual contingency to which they expose themselves. Besides, both experiments converge with previous empirical data, showing a persistent bias that does not vanish as training proceeds. These findings contrast with the preasymptotic and transitory effect predicted by several theoretical models.     

Effects of long-term blindness on preparatory emg modulation in humans performing landing movements

To investigate the long-term effect of blindness on the task of leaping down to a lower landing surface, five blind individuals were compared with 10 sighted individuals who performed landing movements with and without sight. Participants performed six consecutive drop-landings from four different heights, during which the prelanding modulation of EMG timing and amplitude in four lower-limb muscles were recorded. Analysis showed that blind individuals showed specific prelanding EMG modulation, suggesting that long-term dependence on somesthetic and vestibular cues leads to different preparatory measures for vertical falls.