Held and Hein (1963) demonstrated that kittens actively exploring their environment developed normal visually guided behavior, while passively moved kittens did not, despite receiving the same visual stimulation.
This seminal study highlighted the crucial role of self-produced movement in the development of visual perception and coordination. It challenged the idea that passive exposure to visual stimuli alone was enough for normal development.
Held, R., & Hein, A. (1963). Movement-produced stimulation in the development of visually guided behavior. Journal of Comparative and Physiological Psychology, 56 (5), 872.
Background
Previous evidence from two sources suggested that the visual world could be reinterpreted, i.e., that there is a degree of plasticity in the neural systems responsible for perceptual development.
Firstly, restricting the visual experience of newborn animals, known as neonatal deprivation, affects the development of spatial perception and coordination. Deprivation here means withholding a normal early experience. Its role in development is then tested by comparing outcomes with and without it.
Riesen and Aarons (1959) and Riesen (1961) reared cats in darkness or diffuse, patternless light.
They found lasting deficits in visually guided behaviour, and even changes in the visual system itself.
That work showed early visual experience is genuinely necessary. But it left one thing unclear. A dark-reared animal is deprived of both patterned input and movement together, so it could not show which one mattered.
Secondly, adult human perception also displays some plasticity, since people can adapt to new perceptual information. Held (1955) demonstrated this experimentally with auditory information, or sound. Held & Hein (1958) did the same with visual information.
In Held’s adult studies, participants who actively moved while viewing a displaced field adapted.
Passively moved participants did not. This earlier finding is what led Held to predict that active movement would also be necessary for perceptual development in young animals.
In addition, case studies suggest that adult human perception is plastic. Examples include adaption to inverted images (e.g., Stratton, 1897) and people who recovered their sight after being blind for many years (e.g., Gregory & Wallace, 1963).
Aim
The aim of Held and Hein’s (1963) study was to investigate whether active, self-produced movement is necessary for the development of visually guided behavior in kittens. It directly challenged the idea that passive exposure to visual stimuli alone is enough for normal development.
The researchers compared kittens that actively explored their environment with kittens that were passively moved through the same environment. Movement was the only thing that differed. This let them isolate the effect of self-directed movement on visual perception and coordination, including depth perception.
Procedure
- Independent variable: the condition of the kitten: active or passive.
- Dependent variable: the perceptual skills and development of the kittens.
Ten pairs of kittens were used, each pair from a different litter (Aged between 8 and 12 weeks). In each pair, one was ‘active’ (A) and one was ‘passive’ (P).
Kitten carosel
The kitten carosel was a specially designed apparatus, consisting of a circular platform with a central vertical axis, was constructed. A horizontal arm extended from the axis, with a kitten gondola suspended from each end of the arm. The gondolas were designed to allow the kittens to move freely within them.
The kittens were placed in the kitten carosel apparatus for three hours a day. Sessions continued until each kitten had developed the visually-guided paw-placement response, up to 63 hours (21 daily sessions).
During this time, the active kittens could actively explore their environment, while the passive kittens were exposed to the same visual stimuli but could not control their own movement.
- Active kittens could actively explore their environment through self-directed movement. They could control their own actions and receive visual, tactile, and proprioceptive feedback due to their movements.
- Passive kittens were exposed to the same visual environment as the active kittens but could not actively explore or interact with it. They received visual input passively, without the opportunity to control their own actions or receive feedback from self-directed movement.
Kitten P travelled in a basket rather than walking. A mechanical linkage moved it along exactly the same path as kitten A: the same clockwise turns, the same trips to the edge and back, the same rise and fall. Kitten P had no control over any of it.
Its legs stuck through the bottom of the basket. It could not move them, but they could slide along the floor as it moved.
Neither kitten could see their own limbs. Both could move their heads freely.
The apparatus was housed in a cylinder with black, white, and metal-colored vertical strips on the walls inside. The center of the roundabout, which was also striped, prevented the kittens from seeing each other.
The pairs spent 3 hours per day in the experimental apparatus, beginning when the active kitten was big enough to move the ‘roundabout’. When not in the experimental apparatus, all kittens were housed in darkness with their mother and littermates.
Testing Visually Guided Behavior
- Visually-guided paw placement: the kitten was held by the experimenter with its head and forelegs free and was carried down to the edge of the table. A kitten with normal visual experience extends its paws, ready to make contact with the surface.
- Avoidance of a visual cliff (Gibson & Walk, 1960): the kitten is placed on the central ‘bridge’ from which it can stay still or walk onto either the ‘shallow’ or ‘deep’ side. A kitten with normal visual experience avoids the ‘deep’ side.
- Blink to an approaching object: the kitten was held still in a standing position and the experimenter brought his hand quickly towards the kitten’s face (stopping just in front of it). A kitten with normal visual experience blinks in response.
In addition, three tests of visual receptors and their responses were conducted:
- Visual pursuit of a moving object: the kitten was shown the experimenter’s hand moving slowly in front of it. The movement of the kitten’s eyes was recorded. A kitten with normal visual experience follows the movement with its eyes.
- Pupillary reflex to light: a torch beam was moved across the eye and the change in pupil size was noted. The pupil of a kitten with normal visual experience shrinks in response.
- Tactual placing response: the kitten was held as in the paw placement test but its front paws were put against the vertical surface of the table. A kitten with normal visual experience responds by moving its paws to the horizontal surface.
Findings
Development of visually guided behavior
All of the active kittens developed a normal visually-guided paw-placement response within 63 hours (21 sessions) or less in the apparatus, most by about 33 hours (11 sessions).
No passive kitten acquired this response.
This held true even after an equivalent length of time to its active littermate.
The blink response followed the same pattern, appearing at the same time as paw placement.
On the same day that each active kitten first showed the paw-placement response, the pair was tested on the visual cliff. They were tested again the next day. The results are shown in Table 1.
All of the active kittens showed normal responses to depth. The passive kittens crossed to the shallow or deep side at random, suggesting they could not discriminate between the two drops.
Specificity and reversibility of the deficit
Normal visual pursuit of a moving object, the pupillary reflex to light, and tactual placing responses were seen in all animals before they were first placed in the apparatus.
The passive kittens’ deficit was therefore specific to visually guided behavior, not a general sensory or motor problem.
The passive kittens were not blind, brain-damaged, or generally impaired. What they lacked was the ability to use vision to guide action.
A sub-group of two passive kittens got extra passive stimulation in the apparatus, between 2 and 10 weeks of age. They were then given an extra two days of free movement in the light and re-tested. They recovered quickly. Both developed normal visually-guided paw placement and visual cliff responses.
The passive rearing had produced a functional deficit, not a permanent structural loss. The missing ingredient, self-produced movement, could be supplied later to remedy it.
Conclusion
The findings fit the idea that self-produced movement and concurrent visual feedback are essential for the development of visually-guided behavior.
Passive visual stimulation alone, even when it is rich and identical in content to what the active kitten received, was not enough on its own. To coordinate vision and action, a kitten had to generate its own movements and experience the sensory changes those movements produced.
Related and Converging Research
The kitten carousel study sits within a cluster of experiments on how early experience shapes perception.
Later work explains why self-produced movement matters, and extends the finding to new studies and species.
The reafference explanation
Held’s account of why self-produced movement matters rests on reafference: sensory change that is the direct result of an animal’s own movement. This is different from exafference, sensory change caused by events in the outside world.
The nervous system needs to tell the two apart. It must know, for example, that the visual world only seems to “swing” because the animal turned its own head.
Held proposed that the brain keeps an internal copy of each motor command it issues, called an efference copy. It compares this copy against the sensory feedback that actually arrives, to work out which changes were self-caused.
The passive kitten could never make this comparison. It received visual change without ever issuing the movement commands that should have predicted it. So it had no way to learn the link between its own action and what it saw.
The active kitten had both halves of the comparison and so could build that link.
Dissociating the components of placing (Hein & Held, 1967)
Aim: to test whether the visually-guided paw-placing response has separate parts with different experience requirements.
Method: kittens were given controlled exposure in which they could see the environment but not their own moving limbs. Placing was then tested with the limb visible and with it hidden.
Findings: the paw’s basic extension could appear from mere exposure. But accurate, visually guided placement needed the kitten to have seen its own limb move under its own control.
Conclusion: visually guided reaching is not one single reflex. Its precise guidance depends specifically on seeing self-produced limb movement, refining the original 1963 conclusion. This means the reflex’s basic trigger and its accurate visual guidance can be pulled apart experimentally, something the simpler 1963 test could not show.
How early visual experience shapes the brain (Blakemore & Cooper, 1970)
Aim: to test whether early visual experience physically tunes the developing visual cortex.
Method: kittens were reared in darkness except for daily exposure in a drum painted with only vertical or only horizontal stripes. They wore a collar that stopped them seeing their own bodies. Their cortical neurons were later recorded.
Findings: the cats were behaviourally “blind” to contours of the orientation they had never seen, and their visual-cortex neurons responded almost only to the orientation they had been reared with.
Conclusion: early visual experience sculpts the brain’s own architecture. This gives a physical, neural counterpart to the behavioural plasticity Held and Hein reported.
It also provides a physiological counterpart to the developmental window in which the carousel manipulation operated, a window now often called a sensitive period.
Strengths
High level of control
The study was conducted under highly controlled laboratory conditions. The apparatus allowed for precise manipulation of the independent variable: active versus passive movement. The passive kitten’s motion was imposed by the apparatus, not generated by the kitten itself.
This high level of control helps to establish a clear cause-and-effect relationship between the variables. It strengthens the study’s internal validity. Nothing else plausibly explains the difference between the two kittens.
Replicable
The standardization of the procedure in Held and Hein’s (1963) study makes it easier to replicate.
Held and Hein (1963) standardized their procedure using the same apparatus, exposure duration, visual stimulation, and testing procedures for all kittens. The apparatus provided identical physical environments, while the exposure duration of three hours a day for eight weeks was consistent.
Reduced bias
Using pairs of kittens minimized the potential for individual differences among the subjects to influence the results. Each pair came from a different litter, and the passive kitten’s movement was mechanically yoked to its active littermate.
This meant the two kittens in a pair received essentially identical visual stimulation, leaving self-produced movement as the main difference between them.
Weaknesses
Not generalizable
The study used a small sample size and a specific animal species (kittens), which limits the generalizability of the findings to other species, including humans.
The development of visually guided behavior in kittens may not directly translate to the human experience, as there are differences in brain structure and developmental processes.
Lack of ecological validity
The kittens in the study were exposed to a limited set of environmental stimuli within the experimental apparatus.
The study’s artificial laboratory setting and apparatus may not accurately represent the complex, real-world environments in which animals and humans typically develop.
As a result, the findings may not fully capture the intricacies of perceptual and motor development in real-world contexts.
Ethical issues
The study raises ethical concerns regarding animal welfare.
The kittens were kept in darkness and confined to cages for extended periods, which may have caused distress and potentially harmful effects on their development.
Manipulating the kittens’ early sensory experiences and creating a passive condition that hindered normal development may be considered unethical by contemporary standards.
By modern standards, including today’s licensing and ethical-review frameworks for animal research, a deprivation study like this would face intense scrutiny. It would very likely not be permitted in this form.
Alternative Explanations
Held and Hein consider two possible alternative explanations for their findings.
The first is that deprivation caused physical damage (atrophy) in the passive kittens, not a lack of self-produced movement. This is unlikely. The passive kittens showed normal physiological responses on the three additional tests, and could perform the tactual placing response normally.
Such rapid recovery would also be hard to explain if real physical damage had occurred.
The second explanation is emotional response to release from deprivation during testing, not movement itself. Held and Hein reject this too. The restriction of the P and A kittens was so similar that neither showed more fear or excitement than the other in the new test situations.
Contemporary Research
The core principle, that coupling movement to its own feedback drives development, has been retested with modern methods. Mice reared in virtual reality under normal visuomotor coupling, where visual flow matched their own running, developed typical responses in visual-cortex neurons to mismatches between movement and vision.
Mice reared with the same visual input decoupled from their movement, a modern version of the yoked passive kitten, did not (Attinger et al., 2017).
The principle also extends to human development and adult learning. Infants given early powered locomotor experience grew wary of drop-offs sooner than crawling age alone predicted (Dahl et al., 2013). This showed that self-produced movement, not maturation, drives caution around heights.
Adult participants navigating a virtual environment on foot found hidden targets far more efficiently than those who only viewed the same scene (Ruddle & Lessels, 2006).
References
Attinger, A., Wang, B., & Keller, G. B. (2017) Visuomotor coupling shapes the functional development of mouse visual cortex. Cell, 169(7): 1291-1302.
Blakemore, C., & Cooper, G. F. (1970) Development of the brain depends on the visual environment. Nature, 228: 477-478.
Dahl, A., Campos, J. J., Anderson, D. I., Uchiyama, I., Witherington, D. C., Ueno, M., Poutrain-Lejeune, L., & Barbu-Roth, M. (2013) The epigenesis of wariness of heights. Psychological Science, 24(7): 1361-1367.
Gibson, E. J., & Walk, R. D. (1960) The “visual cliff.” Scientific American, 202(4): 64-71.
Gregory RL & Wallace JG (1963) Recovery from early blindness: a case study, in RL Gregory (ed) Concepts and Mechanisms of Perception (1974), pp 65-129. London: Duckworth.
Hein, A., & Held, R. (1967) Dissociation of the visual placing response into elicited and guided components. Science, 158: 390-392.
Held R (1955) Shifts in binaural localization after prolonged exposures to atypical combinations of stimuli. American Journal of Psychology, 68: 526-48.
Held R & Hein A (1958) Adaptation of disarranged hand-eye coordination contingent upon re-afferent stimulation. Perception & Motor Skills, 8: 87-90.
Held, R., & Hein, A. (1963). Movement-produced stimulation in the development of visually guided behavior. Journal of Comparative and Physiological Psychology, 56 (5), 872.
Riesen AH & Aarons L (1959) Visual movement and intensity discrimination in cats after early deprivation of pattern vision. Journal of Comparative Physiology & Psychology, 52: 142-9.
Riesen AH (1961) Studying perceptual development using the technique of sensory deprivation. Journal of Nervous & Mental Diseases, 132: 21-5.
Ruddle, R. A., & Lessels, S. (2006) For efficient navigational search, humans require full physical movement, but not a rich visual scene. Psychological Science, 17(6): 460-465.
Stratton GM (1897) Vision without inversion of the retinal image. Psychological Review, 4: 341.
