Visual discrimination learning

Arthur, D and Levin, E. D. (2001). Spatial and non-spatial visual discrimination learning in zebrafish (Danio rerio), Anim. Cogn. 4, 125-131. 

The results are inconsistent with those of the previous study, to the extent that there was no significant difference in the visual discrimination learning between the groups. In the spatial learning task there were significant differences in the number of days required to reach criterion, with the performance of both maternally and permanently exposed groups inferior to that of controls. 

In contrast to previous observations there were no group differences for errors in the acquisition phase of visual discrimination learning at the age of 100 days. After 6 weeks retention of the task was significantly impaired (p < 0.01 Figure 1) in all lead-exposed groups as compared to controls. There were no differences between maternally and permanently exposed animals... 

Figure 1 Visual discrimination, learning. Mean error scores + confidence limits for control, maternal (750 Co) and permanent (750 ppm) lead-exposed rats. Both treated groups were significantly different (p < 0.01) from controls in the retention part...

Lashley jumping stand A device for testing visual discrimination learning. Two patterns are simultaneously displayed on two different doors and the one with the false pattern is locked. The rat has to cross (originally to jump) and pass through the door with the correct pattern to get a reward. 

Lambs exposed to low levels (350 pg Pb/L blood) Impaired visual discrimination and learning 17... 

Butter, Robert A. 1957a. "Discrimination Learning by Rhesus Monkeys to Auditory Incentives." Journal of Comparative and Physiological Psychology 50 239-41. ------. 1957b. "The Effect of Deprivation of Visual Incentives on Visual Exploration Motivation in Monkeys." Journal of Comparative and Physiological Psychology 50 177-79. 

On a task of visual discrimination - the Karni-Sagi task, for example - individuals improve their performance without knowing how or why (as they learn the task) after sleep they then do better... 

Rapp PR (1990) Visual discrimination and reversal learning in the aged monkey (Macaca mulatta). Behav Neurosci 104 876-884... 

Myhrer, T. (2000). Effects of selective perirhinal and postrhinal lesions on acquisition and retention of a visual discrimination task in rats. Neurobiol. Learn. Mem. 73 68-78. 

Studies with human infants find that at even one or two days of age, they are able to perform detailed visual discriminations, and they show preferences for visually complex or novel stimuli. While this line of research cannot prove the ability is not learned, it does lend support to these abilities being present at birth in some form. 

Aiger TG (1988) Delta-9-tetrahydrocannabinol impairs visual recognition memory but not discrimination learning in rhesus monkeys. Psychopharmacology (Berl) 95 507-511 Al-Hayani A, Davies SN (2000) Cannabinoid receptor mediated inhibition of excitatory... 

In the raty dizocilpine (75 Jig/kg) had no effect on the acquisition of a spatial discrimination task in a Y-maze, but disrupted reversal learning (Cross et al. 1995). Both the acquisition and reversal of a visual discrimination task were impaired following dizocilpine (75 ig/kg). Dizocilpine (40 ig/kg) also disrupted performance of a five-choice visual reaction time task. 

Winneke et al (1982b) carried out an interesting study which demonstrates how relevant the nature of the learning task is. In their study rats were dosed pre- and post-natally with lead. Animals were tested on a two-way active avoidance task, and later on a visual discrimination task. In the discrimination task the performance of lead-dosed animals was inferior to the controls. In the avoidance task the performance of animals improved significantly in a dose-related fashion, with increasing lead level. 

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