Where do the ventral (what) and dorsal (where) visual streams run?
From the primary visual cortex at the back of the occipital lobe, vision runs on in two streams: a ventral stream down into the temporal lobe that recognises what you are looking at, and a dorsal stream up into the parietal lobe that works out where it is and guides your hand and eyes to it. [1][2][3]
A stream is a chain of cortical areas, not one shape in this atlas; lit: the parts each stream ends in, and the lobe both start from.
The 3D brain needs JavaScript. The legend below still names where each stream starts and ends.
The brain starts seen from the left and a little behind: the shared start is at the back, the ventral stream runs forward along the underside, the dorsal stream up over the top. The shared start is lit in pink (the occipital lobe), the ventral stream in blue (the fusiform gyrus and the inferior temporal gyrus), the dorsal stream in orange (the superior parietal lobule). Drag to turn, pinch or scroll to zoom; tap a lit part to name it.
The streams themselves are not drawn: BodyParts3D has no shape for the visual areas they pass through (V2, V4, area MT) or for the intraparietal sulcus, so each stream lights the whole gyrus or lobule its later areas lie on, on both sides of the brain. The inferior parietal lobule below the sulcus is not lit, and V1 is lit as the whole occipital lobe. [4][2][5]
The two streams: which colour is which
Shared start: the occipital lobe, lit in pink: the occipital lobe, on both sides of the brain.
Both streams begin in the primary visual cortex (V1) and pass through visual area V2 next to it, in the occipital lobe, before they part. [2][1]
Recognising objects and faces: it runs from V1 through V2 and V4 to the inferior temporal cortex, a high level of the stream that represents objects, places, faces and colours. On the fusiform gyrus, the largest structure of the ventral temporal cortex, lies the fusiform face area, thought to play a key role in processing faces. [1][2][6][7]
Dorsal stream: “where” or “how”, lit in orange: the superior parietal lobule, on both sides of the brain.
Where things are, and guiding action: it runs from V1 to the posterior parietal cortex. Areas in the intraparietal sulcus, the groove along the lower edge of the superior parietal lobule, steer the eyes, reaching and grasping; the lobule itself takes in much visual input and input from the hand and is involved in spatial orientation. [1][8][5]
The two streams are not sealed off from each other. They are interconnected, a 2009 review of the evidence concluded that their independence had been overemphasised, and the current view is of considerable interaction between vision for recognising and vision for acting. [1]
More about the two visual streams
Other names: two-streams hypothesis, two visual systems, what and where pathways, ventral stream (what pathway), dorsal stream (where pathway, how pathway) [1][2]
Leslie Ungerleider and Mortimer Mishkin proposed the split in 1982, from experiments in monkeys: a ventral stream for what an object is and a dorsal stream for where it is. [1]
In 1992 Melvyn Goodale and David Milner recast it as vision for perception versus vision for action. On their account the dorsal stream turns what the eyes see into viewer-centred coordinates for a movement, which is why it is now often called the “how” pathway. [9][1]
The two are tuned differently: the ventral stream to fine detail, mainly from the centre of gaze, and relatively slow; the dorsal stream to motion across the whole retina, and relatively fast. [1]
Moving along the ventral stream from V1 to the front of the inferior temporal cortex, receptive fields grow larger, respond later and are tuned to more complex features. [1]
The ventral stream reaches temporal-lobe structures where it begins to meet non-visual cortex and may help what you see become memory; the dorsal stream enters the parietal lobe beside the body’s touch and position areas and can then influence the frontal lobe, where movement begins. [3]
The dorsal stream passes area MT (V5), the motion area, on its way up; the same two-stream idea was later applied to hearing, with ventral and dorsal routes out of the auditory cortex. [2][1]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); it has no shape for single visual areas, so a stream is shown by the parts its areas lie on.