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At least 1,657 records · Page 92Linked to original sources
PubMed2003

Mental rotation delays the heart beat: probing the central processing bottleneck.

We tested the hypothesis that mental rotation would delay response-related processing as indicated by transient slowing of the heart beat. Thirty college-age subjects (half female) were presented with normal and mirror image letters rotated at 0, 60, 120, and 180 degrees. Three letters were assigned to a right-hand response; a separate three to a left-hand response. Responses were only required for letters in one orientation, mirror or normal. Continuous measures of interbeat interval (IBI) of the heart, respiration, and muscle tension were collected. Performance results were largely consistent with prior findings. Greater angular displacement of the stimuli was associated with greater lengthening of IBI immediately after the stimulus. IBI was influenced equally by angle of rotation in respond and inhibit trials. The lengthening of IBI was interpreted as due to a delay in response selection and execution due to mental rotation.

Adult↗
PubMedDate not supplied

The S-R information stream: where's the filter?

Pavlovian conditioning procedures, in which events such as tastes, lights, and sounds become predictors of food, water, and shocks, have been used for studying the role of the information filter in the selection of conditioned responses. Different models posit the filter at different locations in the S-R stream, but most models suggest either a pre-encoding filter, in which much information is discarded at an early stage of processing, or a post-encoding filter, in which the information is stored but not subsequently expressed in behavior. A selective review of the literature on cue-competition effects reveals a plethora of phenomena that support a post-encoding, but not a pre-encoding filter in Pavlovian processes.

Animals↗
PubMed1996

Interaction with autonomy: multiple output models and the inadequacy of the Great Divide.

There are currently a number of psycholinguistic models in which processing at a particular level of representation is characterized by the generation of multiple outputs, with resolution--but not generation--involving the use of information from higher levels of processing. Surprisingly, models with this architecture have been characterized as autonomous within the domain of word recognition but as interactive within the domain of sentence processing. We suggest that the apparent confusion is not, as might be assumed, due to fundamental differences between lexical and syntactic processing. Rather, we believe that the labels in each domain were chosen in order to obtain maximal contrast between a new model and the model or models that were currently dominating the field. The contradiction serves to highlight the inadequacy of a simple autonomy/interaction dichotomy for characterizing the architectures of current processing models.

Humans↗
PubMed1994

[On the finger-drawing strategy in recognition of random shapes].

The present study was designed to identify the memory-enhancing factor of finger-drawing strategy, and investigate the relationship between finger-drawing and semantic processing of random shapes. Forty subjects were randomly assigned to one of the five conditions: imagery encoding, verbal encoding, finger-drawing for encoding, finger-drawing for searching, and finger-drawing for both encoding and searching, and performed recognition tasks of random shapes. Results indicated that in the two conditions under which finger-drawing was used for encoding, recognition of complex shapes was superior to that of simple ones. No differences were found for those of high and low associative shapes. Verbal reports of the subjects indicated that finger-drawing for encoding prevented them from naming the shapes. In contrast, in the other three conditions under which finger-drawing was not used for encoding, recognition of simple shapes was superior to that of complex ones. Also, recognition of high associative shapes was superior to that of low ones. These results suggest that kinetic representation, rather than amount of attention, is responsible for the memory-facilitating effect of finger-drawing, and that finger-drawing for encoding inhibits active semantic processing.

Adult↗
PubMed1994

[The effects of descriptive forms of speech act in stories on recognition memory].

A speech act may be described as a sentence corresponding to locutionary act (L-sentence), illocutionary act (I-sentence), or perlocutionary act (P-sentence). The purpose of our research is to examine the effects of descriptive forms of speech acts in stories on recognition memory. Subjects read stories and received unexpected sentence recognition memory test either immediately, an hour later, or four hours later. They rated the degree of confidence of recognition judgement on 7-point scale. The results were as follows: (a) The sentence which had been actually presented in text was recognized correctly with higher confidence, independent of the descriptive forms, (b) The descriptive form in text did not influence the recognition rating by itself, (c) P-sentence tended to be judged as 'not actually presented in text' compared with L-sentence or I-sentence, (d) The recognition time was shortest under the 4-hours-delay condition. These results were discussed in terms of memory representation of sentences and recognition processes.

Adult↗
PubMed1995

Oscillations for rapid selection of neural activities based on spike timing.

In cortical information processing, neuronal inputs are transformed into sequences of action potentials. However, the neural codes used for embedding information in the spike trains remain unclear. Here a neural network consisting of recurrent inhibitory connections is shown to achieve selective activation and inactivation of neurones very efficiently according to spike timing rather than firing rates, when they are stimulated by periodic spike trains. Oscillatory neural activities serve as an accurate clock for the spike-timing code utilized in the rapid selection of neural activities. These results suggest that differences in spike timing of < 1 ms can be of functional significance in certain neural information processing.

Action Potentials↗
PubMed1995

Neurofilament protein defines regional patterns of cortical organization in the macaque monkey visual system: a quantitative immunohistochemical analysis.

Visual function in monkeys is subserved at the cortical level by a large number of areas defined by their specific physiological properties and connectivity patterns. For most of these cortical fields, a precise index of their degree of anatomical specialization has not yet been defined, although many regional patterns have been described using Nissl or myelin stains. In the present study, an attempt has been made to elucidate the regional characteristics, and to varying degrees boundaries, of several visual cortical areas in the macaque monkey using an antibody to neurofilament protein (SMI32). This antibody labels a subset of pyramidal neurons with highly specific regional and laminar distribution patterns in the cerebral cortex. Based on the staining patterns and regional quantitative analysis, as many as 28 cortical fields were reliably identified. Each field had a homogeneous distribution of labeled neurons, except area V1, where increases in layer IVB cell and in Meynert cell counts paralleled the increase in the degree of eccentricity in the visual field representation. Within the occipitotemporal pathway, areas V3 and V4 and fields in the inferior temporal cortex were characterized by a distinct population of neurofilament-rich neurons in layers II-IIIa, whereas areas located in the parietal cortex and part of the occipitoparietal pathway had a consistent population of large labeled neurons in layer Va. The mediotemporal areas MT and MST displayed a distinct population of densely labeled neurons in layer VI. Quantitative analysis of the laminar distribution of the labeled neurons demonstrated that the visual cortical areas could be grouped in four hierarchical levels based on the ratio of neuron counts between infragranular and supragranular layers, with the first (areas V1, V2, V3, and V3A) and third (temporal and parietal regions) levels characterized by low ratios and the second (areas MT, MST, and V4) and fourth (frontal regions) levels characterized by high to very high ratios. Such density trends may correspond to differential representation of corticocortically (and corticosubcortically) projecting neurons at several functional steps in the integration of the visual stimuli. In this context, it is possible that neurofilament protein is crucial for the unique capacity of certain subsets of neurons to perform the highly precise mapping functions of the monkey visual system.

Animals↗
PubMed2001

Bilateral subthalamic nucleus stimulation does not improve prolonged P300 latencies in Parkinson's disease.

Bilateral deep brain stimulation is an effective treatment for most motor signs of Parkinson's disease (PD), but the effects on cognitive functions are less clear. We therefore examined the effects of bilateral deep brain stimulation on central information processing, using the event-related auditory P300 potential as an electrophysiological index of mental chronometry. Eight PD patients with bilateral stimulators within the subthalamic nuclei (STN) and eight age-matched controls participated. Patients were examined after overnight withdrawal of antiparkinson medication, both "on" and "off" stimulation (in random sequence). The P300 and reaction times were recorded using an auditory oddball paradigm. P300 latencies were prolonged in PD patients off stimulation (440 +/- 45 ms) compared to controls (397 +/- 16 ms; P < 0.05). STN stimulation significantly reduced clinical disease severity (as indexed by the Unified Parkinson's Disease Rating Scale) and markedly improved reaction times, but did not improve the prolonged P300 latencies in PD patients (429 +/- 36 ms). These results confirm that P300 latencies are prolonged in PD. Significantly, bilateral STN stimulation did not improve this electrophysiological measure of cognitive impairment, even though motor disability was markedly reduced. This suggests that some dopa-responsive features are resistant to STN stimulation, possibly due to involvement of dopaminergic deficits outside the nigrostriatal pathway, which are not influenced by outflow from the STN.

Aged↗
PubMed1981

Should general hospitals accept involuntary psychiatric patients? A panel discussion.

The issue of whether involuntary patients can be treated safely and effectively on inpatient psychiatry units of general hospitals is addressed from several points of view. Parallels are drawn between contemporary reform efforts and 19th century hospital psychiatry, and the danger of repeating errors of the past is pointed out. An account follows, illustrating the recent planning process for mental health care in Massachusetts and recommending the active participation of psychiatrists in that process. Also discussed are the differences in the process of establishing a treatment alliance with voluntary and involuntary patients. The practical considerations in the development of a locked unit in a general hospital area explored, with respect to its effect on reimbursement, the private practice model, and the length and appropriateness of stay. In conclusion, the shared concern is stated that, in respect to making the transition from one system of care to another, safeguards be built in to protect and expand good treatment.

Commitment of Persons with Psychiatric Disorders↗
PubMed2006

Neural correlates of a mystical experience in Carmelite nuns.

The main goal of this functional magnetic resonance imaging (fMRI) study was to identify the neural correlates of a mystical experience. The brain activity of Carmelite nuns was measured while they were subjectively in a state of union with God. This state was associated with significant loci of activation in the right medial orbitofrontal cortex, right middle temporal cortex, right inferior and superior parietal lobules, right caudate, left medial prefrontal cortex, left anterior cingulate cortex, left inferior parietal lobule, left insula, left caudate, and left brainstem. Other loci of activation were seen in the extra-striate visual cortex. These results suggest that mystical experiences are mediated by several brain regions and systems.

Adult↗
PubMed1993

Towards models of tasks and task complexity in supervisory control applications.

Dynamic task environments in supervisory control situations differ from those traditionally investigated in problem-solving research in that (1) several task goals exist in parallel, (2) task goals change dynamically as the behaviour of the technical process changes, and (3) information required to accomplish task goals changes across time. In the present work, it is suggested that such dynamic task environments can be described using two types of task goal networks, namely a control task goal (CTG) network and an information processing goal (IPG) network. CTG networks are generated by analysis of the operational states required to produce the commodity for which a technical system has been designed. For example, such analyses can be performed using approaches such as Mitchell's operator function model or canonical means-end analyses. IPG networks are generated by using the recently proposed functional information and knowledge acquisition (FIKA) modelling technique. Two examples from different domains illustrate how these task goals networks can be used to describe dynamic task environments. Finally, two different ways of using the task modelling approach are briefly discussed.

Computer Communication Networks↗