Vision - Psychobiology

Approximately ___% of the cerebral cortex plays a direct role in the analysis of visual information.

Our eyes detect the prescence of ___.

For humans, light is a narrow band of the spectrum of ___.

The image must be focused on the ___ for us to see.

The ___ contains photoreceptors.

Humans have ___ million rods.

Humans have ___ million cones.

___ are more sensitive to light.

___ provide us with most of the information about our environment.

We use ___ vision in a very dimly lighted environment.

___ are responsible for daytime vision.

___ are most prevalent in the peripheral retina.

The fovea contains only ____.

The fovea is the central region of the retina which mediates our most ___ vision.

___ only provide onochromatic information.

___ are reponsible for colour vision.

Photoreceptors form synapses with ____ cells.

Bipolar neurones form synapses with ___ cells.

___ cells are neurones whose axons travel through the optic nerves and carry visual information to the rest of the brain.

What are the two parts of photopigment molecules?

Opsin is a protein, retinal is a ____.

Axons of retinal ganglion cells bring information to the rest of the brain by ascending through the optic nerves to the ___ of the thalamus.

The LGN contains ___ layers of neurones.

The inner two layers of the LGN are ____.

The outer four layers of the LGN are ___.

The LGN projects into the _____ cortex.

Optic nerves join together at the base of the brain to form the ____.

Axons from ganglion cells cross the optic chiasm and ascend to the LGN on the ___ side of the brain.

What is the term for the portion of the visual field in which the presentation of visual stimuli will produce an alteration in the firing rate of a particular neurone?

In the periphery of the retina, many receptors converge onto a _____.

In the fovea, there are approximately equal numbers of ganglion cells and ____

Foveal vision is very ___ due to there being approximately equal numbers of ganglion cells and cones.

Ganglion cells normally fire at a relatively ___ rate.

The ____ organisation of ganglion cells enhances our ability to detect outlines of objects, even when the contrast between the object and the background is low.

Each ganglion cell receives information from ____.

The receptive field of most retinal ganglion cells consists of two concentric circles, with the cells becoming ___when light falls in one region and ___when it falls in the other.

___ cells are excited by light in the centre.

___ cells are excited by light in the surround.

___ cells detect dark against light.

___ vision occurs as a result of information provided by three types of cones, each of which is senstive to light of a certain ___.

Absorption charactersitics of the cones are determined by the particular ___ that their photopigment contains.

Area V1 is also known as the ___ cortex.

Parts of area ___ contain a path of cells called blobs which are highly sensitive to colour.

Neurones in area V1 blobs project to ____ of area V2.

Neurones outside of the blobs in area V1 project to ___ and ___ stripes in area V2.

Neurones in the thin stripes of area V2 receive information concerning ___.

The ____ cortex divides into two pathways.

What are the two pathways which the visual association cortex divides into?

The dorsal stream begins in the ____ cortex.

The ventral stream begins in the ____ cortex

The dorsal stream ends in the ___ cortex.

The ventral stream ends in the ___ cortex.

The ___ stream receives mostly magnocellular input.

The ___ stream receives equal input from magnocellular and parvocellular systems.

The ___ stream is involved in perception of form.

The ___ stream is involved in perception of spatial location.

The ___ stream recognises what an object is and what colour it has.

The ___ stream recognises where an object is located and its speed and direction if it is moving.

The response of the ___ system is slow and prolonged, therefore it is able to detect fine details.

Damage to area ___ disrupts colour constancy.

What is the name of the dosorder which means 'vision without colour'?

What is the inability to recognise objects by sight?

Agnosia means failure to ___.

What is the inability to recognise faces?

What is the inability to perceive movement?

Akinatopsia is caused by damage to area ___.

Area ___ is where the split into dorsal and ventral streams occurs.

Damage to area V8 causes ____.

Damage to the ___ stream can cause visual agnosia.

____ are bleached by bright light and are thus not very useful in daylight.

___ are chemicals that release energy when struck by light.

Most of the ganglion cell axons go to the ___.

The LGN is a nucleus of the ____ that is specialised fo visual perception.

What are the two categories of ganglion cells?

Parvocellular cells have smaller cell bodies and a small ____.

Magnocellular cells respond stronly to ___ stimuli and large overall patterns but not to details.

Area ___ responds to any kind of visual stimulus.

The ventral stream is knownn as the ___ pathway.

The dorsal stream is known as the ___ pathway.

The ventral stream is a visual pathway within the ___ cortex

The dorsal stream is a visual pathway within the ___ cortex.

We infer that visual processing is ___, at least up to the level of the LGN.

What is the ability to locate objects within an apparently blind visual field?

One explanation for blindsight after damage to the LGN is that the ___ which receives some visual information controls unconscious visually guided movements.

The magnocellular system is specialised for perception of ___, movement and overall patterns.

The parvocellular system is specialised for perception of colour and ____.

Scotoma is often described as ___.

What condition involves a patient being unable to acknowledge seen stimuli in the affected parts of their visual field.

The inability to recognise colour occurs as a result of damage to area ___.

Photoreceptors transduce light energy into ___.

What ensures that there are two separate functions going on throughout visual processing?

How can we tell that certain areas of the brain deal with different aspects of processing?

How many types of cnes are there?

The centre-surround receptive fields in the ganglion cells shows that colour opponent input ccurs at an ___ stage of visual processing.

Which pathway deals with movement and luminance?

The LGN projects onto the ___.

The ___ cortex is classified into six regions.

Within area V1, the blobs are involved in ___ and ___ perception.

Within area V1, the interblobs are involved in ___ and ___.

The three types of striples in area V2 show that there is now a ___ separation of function.

The thin stripes in area V2 deal with ___ information.

The thick stripes in area V2 deal with ___ information.

The pale stripes in area V2 deal with ___ information.

___% of the occipital cortex is devoted to areas V1 and V2.

What are the three types of cones?

Trichromats and dichromats have only two types of ___.

Damage to the optic nerve causes ___.

___ is a loss of/poor vision. This occurs when there is low level damage to the optic nerve, however we must be careful as the deficits are similar to those in higher areas.

Scotoma or blind spot occurs as a result of damage to area ___.

With scotoma, there is a perception of visual noise but not form or ___.

There has been some ___for patients with damage to area V1, which indicates that some information may go to area V2 then feed back to V1.

The fact that damage to area ___can cause a loss of dreams and memory for colour indicates that we must have to tap down to low level areas

What is a change of light which illustrates the corner of an object?

The fact that there is little or no reduction in the firing range of area V5 when P channels are disrupted suggests that the __ pathway does not go to area V5.

Area V5 has only ___ input.

Low level visual processing occurs from the ___ to ____.

Middle level visual processing occurs from ____ to ___.

High level visual processing occurs in the ___ and ___ cortex areas.

Object recognition dosordes (Agnosias) are not ___ level as it s possible for only specific objects not to be recognised.

What are the two types of agnosia?

Which type of agnosia means that a person is unable to perform a percept of structure (may recognise but cannot name an object)?

Which type of agnosia means that a person is unable to perform a percept of an orject (cannot recognise, copy or match)?

The fact that a person with associative agnosia can describe an object indicates that damage must occur close to areas involved in ___.

A person with visual spatial agnosia cannot find their way through familiar environments using landmarks, but have no problem identifying where an object is. This indicates that there is no ___ stream damage.