Week 2 readings

What is proximal cue-based behaviour?

Behaviour that is cued based on stimuli that spatially co-occur with the goal. This type of behaviour occurs in very young rats.
E.G if the goal IS implied by it’s environment

What is distal cue-based behaviour?

Behaviour that is cued based on stimuli that does not co-occur with the goal, in order to cue this behaviour rats must learn about the spatial location of the goal relative to the distal cues . This type of behaviour occurs only in older rats.
E,g if a goal is NOT implied by its environment

Explain what the ‘general principal’ of sensory systems is?

The idea that, during development, the ‘lower’ centres of a sensory system have to be developed in order to support primitive reflexive responses, before ‘higher centres’ that are necessary for the acquisition and production of more complex learned behaviours are developed

Describe the first experiment?

Different aged mammals were compared on two different problems. On one problem rats were required to find a visible platform, on the other problems, they were required to find an invisible-hidden platform. In both cases the location in the pool varied from trial to trial.
The IV - was the age of the pups
The DV - was whether the platform was hidden or not – indicating distal vs. proximal cue behaviour.

What were the results of the first experiment?

Pups 19 days or older were able to escape to the platform much faster, whereas the performance of the 17 day-olds was less impressive.

Describe the second experiment?

Different aged mammals were compared on two different problems → as like in the first experiment, however, this time, a cup was placed on the platform to account for different sensory/swimming behaviour.
The IV - was the age of the pups
The DV - was whether the platform was hidden or not – indicating distal vs. proximal cue behaviour.

What were the results of the second experiment?

Pups 17 days or older were much more able to perform compared to the results of the first experiment.
Suggests that with proximal cues, young rats are easily able to guide navigational behaviour in the swimming pool.

Describe the 3rd experiment in the study?

Groups of differently aged pups were trained with 2 sessions of 10 and 12 trials (with 24 hour interval in between) in fixed or random platform sessions. Rats were placed in a swimming pool, their capacity to approach and get onto the platform measured in a test tail.
DV - Quadrant search time, annulus crossing (the amount of times the pups crossed the annulus that previously contained the platform, heading error - the direction to which the pups head was pointed.
IV - random vs. fixed platform training

What were the results of the 3rd experiment

Nineteen-day-old pups are unable or unwilling to use distal cues to find the platform. However, by 21 and 23 days of age, pups can use distal cues, with 23-day-olds performing better than 21-day-olds. This suggests that the ability to navigate using distal cues develops after the ability to use proximal cues.

Describe the 4th experiment in the study?

Attempted to address the confounding variable of different perceptual development in young vs. old rats.
Did this by highlighting the proximal/distal cue, the room was darkened except for an illuminated object of a cup
DV - was still the capacity to search for the platform
IV - Distal vs. Proximal cue - The distal cue was created by placing the hidden platform in an adjacent quadrant from the illumination object, and the proximal cue was created by placing the hidden platform under the illuminated cup.

What were the results of the 4th study?

There were age related differences in the ability of the pup to solve the proximal-cue problem.
The 16 days old did no better, however the older pups greatly benefitted from the easier sensory proximal cues afforded by the illuminated environment.

Describe experiment 5 in the study?

Attempted to test different-aged pups for their capacity to use the illuminated cup as a distal-relational cue to find the hidden platform.
Used very similar structure to the 4th experimental study, in that there is a Distal vs. Proximal cue, and a variance of ages of rat pups.
However, they had 3 different probe trials rather than 1.

What were the results of the 5th study?

Pups 22-23-days-old appear to be able to use the illuminated cup as a relational cue to find the hidden platform In contrast, even though the 18-19-day-old pups can use this stimulus as a proximal cue (Experiment 4), they either cannot or do not use as a distal-relational cue.

Describe experiment 6?

Aimed to test distal-relational cues in the context of older 22-23 day old pups. This conclusion has to qualify because we have not demonstrated that this was the specific cue pup used to solve the problem.
Therefore, in this experiment, the platform was always located in Q2 and the illuminated cup in the adjacent quadrant.
All pups went through 3 x training sessions. (10 trials during session1, and 12 trials on following sessions)
IV - at test, the illuminated cup remained in its training location, but for the other 4 pups it was moved to Q3.
DV - was Annulus crossing and the amount of time spent in both Q2 and in Q4.

Describe the results of experiment 6?

showed that pups used the illuminated cup as as distal-relational cue to locate the hidden platform
Interpretation - pups can at a baseline at 22-23 days old use distally-related cues to navigate to the platform.

What do the experiments generally show about the Jacksonian perspective of brain and behavioural development?

Jacksonian development - one expects to see the emergence of progressively more complex levels of behavioral and intellectual functioning during ontogenesis
The fact that the emergence of distal-cue navigation capacity only emerges as a function of age demonstrates that at least in rats, this theory of behaviour is correct.
I.e. The experiment showed that rats' capacity for proximal navigation (emerges in 17 day old rats) emerges before distal navigation (emerges between 20-23 day old rats).