Task 3 Flashcards
What is haptic perception?
- The use of hands to gather information about the world
- Hands are sensory organs which can be used to gather information about properties of an object (e.g. material properties: texture, temperature. Geometrical properties: shape, size etc.).
Adults use two types of exploratory procedures:
1. Lateral motion (Sensing surfaces)
2. Enclosure (molding edges to detect shape
Which of the two EP can be seen in infants?
Enclosure
What are avoiding reflexes and when do they appear?
Avoiding reflexes are voluntary actions characterized by the infant holding and releasing objects.
They are present a few days after birth
How does haptic perception develop?
8 weeks gestation= Touch sense
Newborn = Grasping reflexes
A few days after birth= Avoiding reflexes – voluntary actions: hold & releasing of objects
Present from birth = Handling of objects
Newborns are able to detect geometrical properties of objects through their grasping and enclosure strategies.
At which age do they start to follow contours of objects using both hands to discriminate between objects based on their rigidness or flexibility, or weight?
4 months
What is haptic memory and when does it develop?
Present in new borns
It is the infants’ uses of enclosure exploratory strategies to encode and recognize info gathered from objects
Infants use their hands to explore the world (haptic memory). Older infants (5 months) show a preference for the right hand when they have to hold objects.
What can explain newborn infants’ lack of hand preferences?
Due to the immaturity of the corpus callosum which connects the two cerebral hemispheres
At what age does hand preference related to haptic perception start to become evident?
2 months : infants retain info better if handled with their left hand
At what age is the preference for using right hand for holding objects and doing tasks present?
from 5 months
As infants get older, they use their left hand to treat surfaces and right hand to localize and transport object.
At what age is this observed?
7 months
Infants can recognize objects they have previously touched by looking longer when new visual stimuli are presented with object which they previously touched but did not see.
At what age is this touch to vision intermodal transfer present and when does it disappear?
Present from birth to 5 months
At 5 months, infants can recognize objects they have previously seen using haptic perception. But they cannot recognize visual stimuli that they have previously touched.
Why is that?
Due to speed of maturation of the peripheral system; while the tactile system has an early appearance, it is slow to develop. In contrast, the visual system develops faster despite appearing at a later stage so now infants primarily use their vision to gather info about the world.
At what age can infants perceive unity in partially occluded objects when analyzing their surface arrangements and motions?
4-5 months
How can haptic perception be measured?
Habituation/dishabituation (without visual control)
Object holding
Cross Modal Tasks
Partially Occluded object tasks
Intermodal Paired Preference
Explain the habituation paradigms in assessing haptic perception
*Tactile and visual space are separated by a cloth screen that prevents the infant from seeing his/her hands and the object, but allows for complete freedom of exploration. Habituation is observed when there is a decrease in holding time of repeated presented objects. Test phase – introduction of new object.
