Effect of Motion on the Recognition of Area by Rhesus Monkeys in a Pseudo-Matching Task

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 249-249
Author(s):  
H Malecki ◽  
S G Rosolen ◽  
R Bonnier
Keyword(s):  
Rhesus Monkeys ◽  
Visual Recognition ◽  
Temporal Cortex ◽  
The Other ◽  
Inferior Temporal Cortex ◽  
Matching Task ◽  
Target Area ◽  
Target Speed ◽  
Cortical Areas ◽  
Better Than

We examined the effect of target motion on the visual recognition of target area in rhesus monkeys. We used a pseudo-matching visual task, where ten adult monkeys were trained to recognise and point out the bigger one of two achromatic squares of different areas but having the same luminance and presented on the same background. The video screen was placed 0.5 m in front of their faces. The two areas were randomly sampled out of five areas (49, 72.25, 100, 132.25, and 169 mm2). The speed of the targets was varied in this paradigm (0, 6, 11, 16, 21, or 26 deg s−1). Performance in terms of area recognition thresholds was calculated for each monkey on the basis of 100 trials in standardised environmental conditions. Statistical analysis showed that performance with a target speed of 16 deg s−1 was significantly better than in the other conditions ( p<0.01). We conclude that this pseudo-matching task, based on a cognitive paradigm, reveals a significant effect of motion on the visual recognition of area in rhesus monkeys. The activities of specific cortical areas (V4 and V5) should be studied by other techniques in order to characterise those involved in remembering an object's qualities and those responding to motion. The links between V4, V5, and inferior temporal cortex could be tested with the aid of this pseudo-matching task.

scholarly journals Better to Be Alone than in Bad Company: Cognate Synonyms Impair Word Learning

2020 ◽  
Vol 10 (8) ◽  
pp. 123
Author(s):  
Eneko Antón ◽  
Jon Andoni Duñabeitia
Keyword(s):  
Word Learning ◽  
Word Association ◽  
Recognition Task ◽  
The Other ◽  
Matching Task ◽  
L2 Acquisition ◽  
New Words ◽  
L2 Word Learning ◽  
Concrete Concepts ◽  
Better Than

The effects of cognate synonymy in L2 word learning are explored. Participants learned the names of well-known concrete concepts in a new fictional language following a picture-word association paradigm. Half of the concepts (set A) had two possible translations in the new language (i.e., both words were synonyms): one was a cognate in participants’ L1 and the other one was not. The other half of the concepts (set B) had only one possible translation in the new language, a non-cognate word. After learning the new words, participants’ memory was tested in a picture-word matching task and a translation recognition task. In line with previous findings, our results clearly indicate that cognates are much easier to learn, as we found that the cognate translation was remembered much better than both its non-cognate synonym and the non-cognate from set B. Our results also seem to suggest that non-cognates without cognate synonyms (set B) are better learned than non-cognates with cognate synonyms (set A). This suggests that, at early stages of L2 acquisition, learning a cognate would produce a poorer acquisition of its non-cognate synonym, as compared to a solely learned non-cognate. These results are discussed in the light of different theories and models of bilingual mental lexicon.

scholarly journals Temporal stability of visually selective responses in intracranial field potentials recorded from human occipital and temporal lobes

2012 ◽  
Vol 108 (11) ◽  
pp. 3073-3086 ◽  
Author(s):  
Arjun K. Bansal ◽  
Jedediah M. Singer ◽  
William S. Anderson ◽  
Alexandra Golby ◽  
Joseph R. Madsen ◽  
...  
Keyword(s):  
Visual Recognition ◽  
Cortical Plasticity ◽  
Temporal Stability ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Field Potentials ◽  
Long Time ◽  
Degree Of Stability ◽  
The Stability ◽  
External Stimuli

The cerebral cortex needs to maintain information for long time periods while at the same time being capable of learning and adapting to changes. The degree of stability of physiological signals in the human brain in response to external stimuli over temporal scales spanning hours to days remains unclear. Here, we quantitatively assessed the stability across sessions of visually selective intracranial field potentials (IFPs) elicited by brief flashes of visual stimuli presented to 27 subjects. The interval between sessions ranged from hours to multiple days. We considered electrodes that showed robust visual selectivity to different shapes; these electrodes were typically located in the inferior occipital gyrus, the inferior temporal cortex, and the fusiform gyrus. We found that IFP responses showed a strong degree of stability across sessions. This stability was evident in averaged responses as well as single-trial decoding analyses, at the image exemplar level as well as at the category level, across different parts of visual cortex, and for three different visual recognition tasks. These results establish a quantitative evaluation of the degree of stationarity of visually selective IFP responses within and across sessions and provide a baseline for studies of cortical plasticity and for the development of brain-machine interfaces.

Enhancement of inferior temporal neurons during visual discrimination

1987 ◽  
Vol 58 (6) ◽  
pp. 1292-1306 ◽  
Author(s):  
B. J. Richmond ◽  
T. Sato
Keyword(s):  
Spatial Attention ◽  
Trial Type ◽  
Discrimination Task ◽  
Temporal Cortex ◽  
Pattern Discrimination ◽  
Response Strength ◽  
The Other ◽  
Inferior Temporal Cortex ◽  
Attention Task ◽  
Type Pattern

1. Previous results have shown that spatially directed attention enhances the stimulus-elicited responses of neurons in some areas of the brain. In the inferior temporal (IT) cortex, however, directing attention toward a stimulus mildly inhibits the responses of the neurons. Inferior temporal cortex is involved in pattern discrimination, but not spatial localization. If enhancement signifies that a neuron is participating in the function for which that part of cortex is responsible, then pattern discrimination, not spatial attention, should enhance responses of IT neurons. The influence of pattern discrimination behavior on the responses of IT neurons was therefore compared with previously reported suppressive influences of both spatial attention and the fixation point. 2. Single IT neurons were recorded from two monkeys while they performed each of five tasks. One task required the monkey to make a pattern discrimination between a bar and a square of light. In the other four tasks the same bar of light appeared, but the focus of spatial attention could differ, and the fixation point could be present or absent. Either attention to (without discrimination of) the bar stimulus or the presence of the fixation point attenuated responses slightly. These two suppressive influences produced a greater attenuation when both were present. 3. The visual conditions and motor requirements when the bar stimulus appeared in the discrimination task were identical to those of the trials in the stimulus attention task. However, one-half of the responsive neurons showed significantly stronger responses to the bar stimulus when it appeared in the discrimination task than when it appeared in the stimulus attention task. For most of these neurons, discrimination just overcame the combined effect of the two suppressive influences. For six other neurons, the response strength was significantly greater during the discrimination task than during any other task. 4. The monkeys achieved an overall correct performance rate of 90% in both the discrimination and stimulus attention tasks. To achieve this performance in the discrimination task they adopted a strategy in which they performed one trial type, bar stimulus attention trials, perfectly (100%) and the other trial type, pattern trials, relatively poorly (84% correct).(ABSTRACT TRUNCATED AT 400 WORDS)

Regional and Laminar Differences in In Vivo Firing Patterns of Primate Cortical Neurons

2005 ◽  
Vol 94 (1) ◽  
pp. 567-575 ◽  
Author(s):  
Shigeru Shinomoto ◽  
Youichi Miyazaki ◽  
Hiroshi Tamura ◽  
Ichiro Fujita
Keyword(s):  
Cortical Neurons ◽  
Temporal Cortex ◽  
Local Variation ◽  
Inferior Temporal Cortex ◽  
Regular Type ◽  
Cortical Areas ◽  
Different Types ◽  
Area Te ◽  
Firing Characteristics

The firing rates of cortical neurons change in time; yet, some aspects of their in vivo firing characteristics remain unchanged and are specific to individual neurons. A recent study has shown that neurons in the monkey medial motor areas can be grouped into 2 firing types, “likely random” and “quasi-regular,” according to a measure of local variation of interspike intervals. In the present study, we extended this analysis to area TE of the inferior temporal cortex and addressed whether this classification applies generally to different cortical areas and whether different types of neurons show different laminar distribution. We found that area TE did consist of 2 groups of neurons with different firing characteristics, one similar to the “likely random” type in the medial motor cortical areas, and the other exhibiting a “clumpy-bursty” firing pattern unique to TE. The quasi-regular type was rarely observed in area TE. The likely random firing type of neuron was more frequently found in layers V–VI than in layers II–III, whereas the opposite was true for the clumpy-bursty firing type. These results show that neocortical areas consist of heterogeneous neurons that differ from one area to another in their basic firing characteristics. Moreover, we show that spike trains obtained from a single cortical neuron can provide a clue that helps to identify its layer localization.

STUDIES ON ALDOSTERONE BIOSYNTHESIS IN VITRO

1970 ◽  
Vol 63 (2) ◽  
pp. 299-312 ◽  
Author(s):  
Dinesh C. Sharma
Keyword(s):  
Rhesus Monkeys ◽  
The Other ◽  
List Type ◽  
Alternate Route ◽  
Data Support ◽  
Main Pathway ◽  
Better Than

ABSTRACT Biosynthesis of 18-hydroxycorticosterone and aldosterone from radioactive progesterone, 11-deoxycorticosterone, 11-dehydrocorticosterone and corticosterone by adrenals of bullfrogs and that of normals as well as gonadectomized Rhesus monkeys was studied in vitro. The adrenals of monkeys were much less active than those of the frogs. Corticosterone and progesterone were more efficiently converted to 18-hydroxycorticosterone and aldosterone by the frog adrenals while the formation of these products from 11-dehydrocorticosterone was very little; the adrenals from the monkeys utilized the latter compound comparaticely better than the other substrates. The data support that the main pathway for aldosterone biosynthesis is progesterone:→ 11-deoxycorticosterone → corticosterone→ 18-OH-corticosterone → aldosterone. The pathway involving 11-dehydroaldosterone, proposed by some workers, is comparatively less efficient for aldosterone biosynthesis but could be involved as an alternate route and a mechanism for limiting the biosynthesis of aldosterone in mammals.

scholarly journals Better to Be Alone Than in Bad Company: Cognate Synonyms Impair Word Learning

2020 ◽  
Author(s):  
Eneko Antón ◽  
Jon Andoni Duñabeitia
Keyword(s):  
Word Learning ◽  
Word Association ◽  
Recognition Task ◽  
The Other ◽  
Matching Task ◽  
L2 Acquisition ◽  
New Words ◽  
L2 Word Learning ◽  
Concrete Concepts ◽  
Better Than

The effects of cognate synonymy in L2 word learning are explored. Participants learned the names of well-known concrete concepts in a new fictional language following a picture-word association paradigm. Half of the concepts (set A) had two possible translations in the new language (i.e., both words were synonyms): one was a cognate in participants&rsquo; L1 and the other one was not. The other half of the concepts (set B) had only one possible translation in the new language, a non-cognate word. After learning the new words, participants&rsquo; memory was tested in a picture-word matching task and a translation recognition task. In line with previous findings, our results clearly indicate that cognates are much easier to learn, as we found that the cognate translation was remembered much better than both its non-cognate synonym and the non-cognate from set B. Our results also seem to suggest that non-cognates without cognate synonyms (set B) are better learned than non-cognates with cognate synonyms (set A). This suggests that, at early stages of L2 acquisition, learning a cognate would produce a poorer acquisition of its non-cognate synonym, as compared to a solely learned non-cognate. These results are discussed under the light of different theories and models of bilingual mental lexicon.

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