scholarly journals Evidence that Octopus is Colour Blind

1977 ◽  
Vol 70 (1) ◽  
pp. 49-55 ◽  
Author(s):  
J. B. MESSENGER
Keyword(s):  
Visual Discrimination ◽  
Training Session ◽  
Octopus Vulgaris ◽  
Biochemical Evidence ◽  
Vertical Rectangle ◽  
Physiological And Biochemical

1. Six octopuses were trained on a series of visual discrimination tasks where the discriminanda were presented simultaneously, and where different tasks alternated in a single training session. 2. All the octopuses could make discriminations based on brightness and orientation over the same period of time. 3. Over a period in which all octopuses discriminated a black from a white vertical rectangle none discriminated a yellow vertical rectangle from a grey (of matching brightness). 4. Over a period in which all octopuses discriminated a vertical from a horizontal grey rectangle none discriminated a violet vertical rectangle from a matching grey. 5. The behaviour of the octopuses was qualitatively different in the hue versus grey situations, their attacks being considerably slower and less certain. 6. These results, which agree with previous behavioural findings and a variety of morphological, physiological and biochemical evidence, make it increasingly probable that Octopus vulgaris is colour blind.

Influence of Previous Preferences on the Memory of Octopus Vulgaris After Removal of the Vertical Lobe

1965 ◽  
Vol 43 (3) ◽  
pp. 595-603
Author(s):  
J. Z. YOUNG
Keyword(s):  
Discrimination Training ◽  
Octopus Vulgaris ◽  
Vertical Rectangle ◽  
Do So

1. Octopuses from which the vertical lobe had been removed attacked a vertical rectangle more readily than a horizontal one when both shapes were moved vertically. 2. During discrimination training the results differed markedly according to which figure was rewarded with food. 3. When a vertical rectangle was positive the excess of attacks at this figure increased both within and between sessions, the animals showing considerable ability to learn. 4. When a horizontal rectangle was the positive figure the responses to it were at first ‘paradoxical’, the negative shape being attacked more often. There was then improvement within each session, but little if any between the sessions. 5. Octopuses without the vertical lobe quickly ceased to attack crabs shown at 4 min. intervals when shocks were given for attacks, and the effect could still be detected 4 hr. later. 6. When crabs were shown at 8 min. intervals, and shocks given for attacks, there was no decline in attacks over fourteen trials. Fifteen hours later, however, some residual signs of the shocks were evident when trials were resumed at 8 min. intervals. Although all of the animals at first attacked they soon stopped doing so. After a further 15 hr. all attacked again but soon ceased to do so after receiving shocks. 7. Normal animals, by contrast, all ceased to attack the crabs shown at 8 min. intervals after receiving four or five shocks. The memory is much more retentive in normal animals, so that 2 days after receiving shocks the octopuses seldom attacked the crabs.

Visual Discrimination Task Improvement: A Multi-Step Process Occurring During Sleep

2000 ◽  
Vol 12 (2) ◽  
pp. 246-254 ◽  
Author(s):  
Robert Stickgold ◽  
Dana Whidbee ◽  
Beth Schirmer ◽  
Vipul Patel ◽  
J. Allan Hobson
Keyword(s):  
Task Performance ◽  
Eye Movement ◽  
Process Modeling ◽  
Visual Discrimination ◽  
Discrimination Task ◽  
Slow Wave Sleep ◽  
Training Session ◽  
Visual Discrimination Task ◽  
Rapid Eye Movement Sleep ◽  
Step Process

Performance on a visual discrimination task shows longterm improvement after a single training session. When tested within 24 hr of training, improvement, was not observed unless subjects obtained at least 6 hr of postraining sleep prior to retesting, in which case improvement was proportional to the amount of sleep in excess of 6 hr. For subjects averaging 8 hr of sleep, overnight improvement was proportional to the amount of slow wave sleep (SWS) in the first quarter of the night, as well as the amount of rapid eye movement sleep (REM) in the last quarter. REM during the intervening 4 hr did not appear to contribute to improvement. A two-step process, modeling throughput as the product of the amount of early SWS and late REM, accounts for 80 percent of intersubject variance. These results suggest that, in the case of this visual discrimination task, both SWS and REM are required to consolidate experience-dependent neuronal changes into a form that supports improved task performance.

Pretilachlor toxicity is decided by discrete photo-acclimatizing conditions: Physiological and biochemical evidence from Anabaena sp. and Nostoc muscorum

2018 ◽  
Vol 156 ◽  
pp. 344-353 ◽  
Author(s):  
Jitendra Kumar ◽  
Anuradha Patel ◽  
Sanjesh Tiwari ◽  
Santwana Tiwari ◽  
Prabhat Kumar Srivastava ◽  
...  
Keyword(s):  
Nostoc Muscorum ◽  
Biochemical Evidence ◽  
Anabaena Sp ◽  
Physiological And Biochemical

Interference in Learning and Lesions in the Visual System of Octopus Vulgaris

Behaviour ◽  
1963 ◽  
Vol 21 (3-4) ◽  
pp. 233-244 ◽  
Author(s):  
J.R. Parriss
Keyword(s):  
Nervous System ◽  
Visual System ◽  
Optic Lobe ◽  
The Other ◽  
Octopus Vulgaris ◽  
Black And White ◽  
Vertical Rectangle ◽  
Improved Performance ◽  
Previous Learning ◽  
Better Than

AbstractTwo groups of Octopuses, one normal and one with lesions in the optic lobe system, were trained on a discrimination between horizontal and vertical rectangles followed by a discrimination with a square and a diamond. They were then retrained on the original horizontal and vertical discrimination. A further group of normal animals were trained on a discrimination between the square and the diamond followed by a discrimination with the horizontal and vertical rectangles. They were then retrained on the original square and diamond discrimination. Results were as follows: 1. Animals with lesions in the optic lobe system showed impairment of relearning following the different and more difficult square and diamond discrimination. Normal animals, on the other hand, showed improved performance under these conditions. 2. In the case of both normal and operated animals the square and diamond discrimination (square positive - diamond negative) was learned less well following the horizontal and vertical rectangle discrimination than when it was learned as a first discrimination by the normal animals. The level of learning with diamond positive- square negative was, however, maintained at the same level as the first discrimination. 3. When the square and diamond discrimination was relearned by the normal group, square positive - diamond negative was relearned less well than first learning, and diamond positive-square negative was not affected by previous learning, thus confirming point 2. 4. At the end of training the operated animals discriminated between black and white circles better than they had re-learned the horizontal and vertical rectangles. These findings have been related to theories of analysing mechanisms in the nervous system of octopus.

scholarly journals From hand to eye: A meta-analysis of the benefit from handwriting training in visual graph recognition

2021 ◽  
Author(s):  
Susana Araújo ◽  
miguel domingues ◽  
Tania Fernandes
Keyword(s):  
Perceptual Learning ◽  
Visual Discrimination ◽  
Meta Analysis ◽  
Training Session ◽  
Coarse Grained ◽  
Cognitive Mechanism ◽  
Fine Grained ◽  
Graph Recognition ◽  
Phonological Training ◽  
Visual Graph

Handwriting (HW) training seems to boost recognition of visual graphs and learning to read more than other learning experiences. However, effects across studies appear to be variable and the underlying cognitive mechanism has been elusive. We thus conducted a meta-analysis on 50 independent experiments (with 1525 participants) to determine the magnitude of this HW benefit in visual graph recognition, while enlightening the underlying cognitive mechanism, by investigating four types of moderators: training program (type of control training, presence/absence of phonological training, and HW tasks adopted); set size and training regime (duration and frequency of training session and total amount of training); granularity of visual discrimination and perceptual learning tasks; and age of participants. The benefit from HW training was moderate-to-large and significant (Hedge’s g = 0.58, SE = .09) and was also modulated by type of control training (larger relative to motor, g = 0.78, than to visual control, g = 0.37), phonological training (larger when it was absent, g = 0.79, than present, g = 0.47), and granularity of visual discrimination (larger for fine-grained, g = 0.93, than coarse-grained, g = 0.19). These results are consistent with symbolic accounts that hold that the advantage from HW training in visual graph recognition is about perceptual learning rather than the motor act. Multiple meta-regressions also revealed that training regime modulated the HW benefit. We conclude that HW training is effective to improve visual graph recognition, and hence, is still relevant for literacy instruction in the present digital era.

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