A long-lasting change in ocular dominance of kitten striate neurons induced by reversible unilateral blockade of tonic retinal discharges

1976 ◽  
Vol 26 (5) ◽  
Author(s):  
T. Kasamatsu
Keyword(s):  
Ocular Dominance ◽  
Striate Neurons ◽  
Lasting Change

Influence of a moving textured background on direction selectivity of cat striate neurons

1987 ◽  
Vol 57 (6) ◽  
pp. 1792-1812 ◽  
Author(s):  
G. A. Orban ◽  
B. Gulyas ◽  
R. Vogels
Keyword(s):  
Ocular Dominance ◽  
Direction Selectivity ◽  
Cortical Cells ◽  
Noise Pattern ◽  
Motion Cues ◽  
Relative Direction ◽  
Striate Neurons ◽  
Experimental Findings ◽  
Dorsal Lateral Geniculate ◽  
Background Motion

The influence of a moving textured background on direction selectivity for a moving bar was tested in 118 striate neurons and in 19 dorsal lateral geniculate neurons of anesthetized and paralyzed cats. In the standard conditions the background was a two-dimensional noise pattern, the bar moved at optimal speed, and its contrast was adjusted to the level producing 50% of the maximum response. These experiments revealed a new typology of cortical cells based on relative direction selectivity. Six different relative-direction-selectivity types are described. Two types of cells were found to have opposite kinds of relative direction selectivity: antiphase direction-selective cells (5% of the cortical sample) preferred the direction of the bar opposite to the direction of background motion, and absolutely direction-selective cells (20% of the cortical sample) kept their direction selectivity for bar motion independently of the background motion. Three types of cortical cells were direction selective for bar motion only in restricted background motion conditions: conditionally direction-selective cells (20% of cortical sample) only expressed their direction selectivity when the bar and the background moved in antiphase, differencing direction-selective cells (5% of the cortical sample) only expressed their direction selectivity when the bar and the background differed in speed, and limited direction-selective cells (20% of the cortical sample) only expressed their direction selectivity for near zero background speeds. The sixth type, relative nondirection-selective cells (30% of the cortical sample and all of the geniculate cells) were direction selective for none of the background motion conditions. These different relative-direction-selectivity types differed in RF organization, in ocular dominance, velocity sensitivity, in laminar distribution, and in distribution in the visual field. The relative-direction-selectivity types were invariant for changes in the contrast and bar speed. The construction of these relative-direction-selectivity types from the geniculate input requires some inhibitory, but mainly facilitatory, intracortical interactions. These experimental findings suggest that area 17 in the cat has the neuronal machinery to extract depth from motion (limited direction-selective cells) and to segregate visual scenes by motion cues (antiphase, conditionally and differencing direction-selective cells).

scholarly journals Norepinephrine Potentiates and Serotonin Depresses Visual Cortical Responses by Transforming Eligibility Traces

2021 ◽  
Author(s):  
Su Z Hong ◽  
Lukas Mesik ◽  
Cooper D Grossman ◽  
Jeremiah Y Cohen ◽  
Boram Lee ◽  
...  
Keyword(s):  
Ocular Dominance ◽  
Visual Responses ◽  
Ocular Dominance Plasticity ◽  
Biological Relevance ◽  
Cortical Responses ◽  
Reinforced Learning ◽  
Visual Cortical ◽  
Hebbian Mechanisms ◽  
Lasting Change

Reinforcement allows organisms to learn which stimuli predict subsequent biological relevance. Hebbian mechanisms of synaptic plasticity are insufficient to account for reinforced learning because neuromodulators signaling biological relevance are delayed with respect to the neural activity associated with the stimulus. A theoretical solution is the concept of eligibility traces (eTraces), silent synaptic processes elicited by activity which upon arrival of a neuromodulator are converted into a lasting change in synaptic strength. Previously we demonstrated in visual cortical slices the Hebbian induction of eTraces and their conversion into LTP and LTD by the retroactive action of norepinephrine and serotonin Here we show in vivo in V1 that the induction of eTraces and their conversion to LTP/D by norepinephrine and serotonin respectively potentiates and depresses visual responses. We also show that the integrity of this process is crucial for ocular dominance plasticity, a canonical model of experience-dependent plasticity.

Discrimination of orientation and position disparities by binocularly activated neurons in cat straite cortex

1977 ◽  
Vol 40 (2) ◽  
pp. 260-283 ◽  
Author(s):  
J. I. Nelson ◽  
H. Kato ◽  
P. O. Bishop
Keyword(s):  
Ocular Dominance ◽  
Stimulus Orientation ◽  
Orientation Tuning ◽  
Simple Cells ◽  
Tuning Curves ◽  
Complex Cells ◽  
Eye Rotation ◽  
Striate Neurons ◽  
The Mean ◽  
Orientation Disparity

1. We have examined and compared the ability of binocularly activated striate neurons to make both position disparity and orientation disparity discrimination in the anesthetized (N2O/O2) and paralyzed cat preparation. 2. Accurate knowledge of eye position is essential for disparity studies. Using a retinal projection technique able to detect eye drifts of less than 3' arc per retinal landmark and less than 18' arc cyclorotation disparity, we determined eye drift during the course of 2- to 4-day experiments. After the initial eye rotation due to the anesthesia and the onset of paralysis (see below), rotational drift thereafter was mainly excyclorotatory and, from all causes, rarely totaled more than 4 degrees disparity. All our data have been corrected for this residual cyclorotatory drift. 3. Optimal stimulus orientation disparities were determined from quantitative monocular orientation tuning curves for 74 binocularly activated striate cells (37 simple, 3 hypercomplex I, 31 complex, 3 hypercomplex II) from nine cats. Without exception, the mean optimal stimulus orientation disparity in each of our animals showed a departure from zero disparity equivalent to an incyclorotation of the eyes (mean, 9.2 degrees; range, 2.7 degrees-15.9 degrees). 4. We attribute this mean optimal stimulus orientation disparity shift to ocular cyclorotation as a result of the initial anesthesia and paralysis. Assuming equal intortion, incyclorotation for each eye averages 4.6 degrees. On the assumption that the mean optimal stimulus orientation disparity is zero in normal life, we pooled results from the nine animals about their individual means. For the 74 cells the resulting distribution of the optimal stimulus orientation disparities had a range of about +/-15 degrees (simple cells: SD 4.9 degrees; complex cells: SD 7.4 degrees). 5. We examined the relationship of the sharpness of the orientation tuning curves to ocular dominance, to absolute orientation preference, and to other unit properties. The striking observation was the high correlation between the sharpness of orientation tuning curves for the two eyes of a binocular neuron. For simple cells the mean difference for the half-widths of half-height was only 2.54 degrees, with sharpness showing a high correlation between the two eyes (r=0.915) over half-width at half-heights ranging from 8.5 degrees to 41.8 degrees. Complex cells showed a similar, albeit weaker, correlation. 6. Having shown that, assessed monocularly binocular units show different orientation tunings in the two eyes, we undertook binocular experiments to ascertain if these differences were the optimal disparities of sharply tuned stimulus orientation disparity channels. Using a matrix stimulation paradigm to minimize the effects of spontaneous changes in responsiveness, we have simultaneously extracted bionocular stimulus orientation disparity and position disparity tuning curves from single striate neurons...

Race and the Epigenetics of Memory

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Gabriela Soto Laveaga
Keyword(s):  
Social Construction ◽  
Dna Analysis ◽  
Historical Context ◽  
Neural Function ◽  
Social Constructions ◽  
Race Science ◽  
The Social ◽  
Black Bodies ◽  
Dead Bodies ◽  
Lasting Change

In my brief response to Terence Keel’s essay “Race on Both Sides of the Razor,” I focus on something as pertinent as alleles and social construction: how we write history and how we memorialize the past. Current DNA analysis promises to remap our past and interrogate certainties that we have taken for granted. For the purposes of this commentary I call this displacing of known histories the epigenetics of memory. Just as environmental stimuli rouse epigenetic mechanisms to produce lasting change in behavior and neural function, the unearthing of forgotten bodies, forgotten lives, has a measurable effect on how we act and think and what we believe. The act of writing history, memorializing the lives of others, is a stimulus that reshapes who and what we are. We cannot disentangle the discussion about the social construction of race and biological determinism from the ways in which we have written—and must write going forward—about race. To the debate about social construction and biological variation we must add the heft of historical context, which allows us to place these two ideas in dialogue with each other. Consequently, before addressing the themes in Keel’s provocative opening essay and John Hartigan’s response, I speak about dead bodies—specifically, cemeteries for Black bodies. Three examples—one each from Atlanta, Georgia; Rio de Janeiro, Brazil; and Mexico—illustrate how dead bodies must enter our current debates about race, science, and social constructions. 

Recognizing a Crisis

2018 ◽  
Author(s):  
Joshua M. Sharfstein
Keyword(s):  
Crisis Management ◽  
Daily Activity ◽  
Wishful Thinking ◽  
Phone Call ◽  
First Order ◽  
Lasting Change

The first order of business in crisis management is figuring out that there is a crisis. Once a brewing crisis is recognized, health officials can organize a coherent response, limit its impact, and even make an early pivot to achieve long-lasting change. Unfortunately, spotting a crisis early is far easier said than done. It’s the rare crisis that announces itself with a phone call 12 hours in advance. Most crises go unnoticed even as clues emerge, lost in the stream of the daily activity of an agency or hidden by biases, assumptions, and wishful thinking. To be successful, officials and their agencies should pursue a proactive strategy to identify crises early. There are three elements of effective crisis detection: spotting signals, pulling in data and assessing the situation, and developing a space and culture to put the pieces of the puzzle together.

scholarly journals Improving Equine Welfare through Human Habit Formation

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2156
Author(s):  
Jo White ◽  
Ruth Sims
Keyword(s):  
Management Practices ◽  
Habit Formation ◽  
Positive Impact ◽  
Proof Of Concept ◽  
Mutual Benefit ◽  
Structured Interviews ◽  
Behavioural Research ◽  
Equine Welfare ◽  
Lasting Change

This paper explores the potential for interventions to develop pro-animal welfare habitual behaviours (PAWHBs) in people to improve the lives of animals. Human behavioural research indicates that opportunities exist to deliver lasting change through developing positive habitual behaviours. The routine nature of many equine care and management practices lends itself to habit formation and maintenance. This proof-of-concept paper aims to evaluate a theory-based intervention of developing and maintaining a PAWHB in people caring for equines. Qualitative research methods were used. A 30 day PAWHB intervention (PAWHBInt) of providing enrichment to an equine by scratching them in a consistent context linked to an existing routine behaviour was undertaken. Participants (n = 9) then engaged in semi-structured interviews that were analysed using thematic analysis, where the participants self-reported the outcomes they observed during the intervention. The study findings suggest that the PAWHBInt had a positive impact on human behaviour and habit formation. The research helps to address the dearth of evidence regarding the application of habit theory to equine welfare interventions and emphasised linking a desired new behaviour to an existing routine behaviour when developing PAWHBs. The research also highlights the role of mutual benefit for human and equine, and emotion in providing feedback and potential reward, supporting the link to the cue-routine-reward principle of habit theory.

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