Neurophilosophy

Archives for January, 2009

Single neurons have RAM-like activity

In his epic poem Visions of the Daughters of Albion, William Blake asks: “Where goest thou O thought? To what remote land is thy flight?” More than two centuries later, memory remains as one of the enduring mysteries of neuroscience, and despite decades of intensive research using modern techniques, we still have no answer to…

Facial sensations modulate speech perception

What sensory cues do we rely on during the perception of speech? Primarily, of course, speech perception involves auditory cues – we pay close attention to the sounds generated by the speaker. Less obviously, the brain also picks up subtle visual cues, such as the movements of the speakers mouth and lips; the importance of…

The delusional brain

Delusions are pathological beliefs which persist despite clear evidence that they are actually false. They can vary widely in content, but are always characterized by the absolute certainty with which they are held. Such beliefs reflect an abnormality of thought processes; they are often bizarre and completely unrelated to conventional cultural or religious belief systems,…

Cellular “tug-of-war” breaks brain symmetry

The brains of vertebrates are asymmetrical, both structurally and functionally. This asymmetry is believed to increase the efficiency of information processing – one hemisphere  is specialized to perform certain functions, so the opposite is left free to perform others. In the human brain, for example, the left hemisphere is specialized for speech. This has been…

The evolution of manual dexterity

The unique capabilities of the human hand enable us to perform extremely fine movements, such as those needed to write or to thread a needle. The emergence of these capabilities was undoubtedly essential in human evolution: a combination of individually movable fingers, opposable thumbs and the ability to move the smallest finger and ring finger…

Brain hacks infographic

The Boston Globe has a cool infographic by Jonah Lehrer and Javier Zarracina, describing five simple ways in which sensory perception can be altered using everyday objects. These include the Ganzfeld procedure, a mild sensory deprivation technique which leads to visual or auditory hallucinations; the Pinocchio illusion,  in which one’s nose is perceived as being…

The harmonic duets of mosquitoes in love

The familiar buzzing sound made by a mosquito may be irritating to us humans, but it is an important mating signal. The sound, produced by the beats of the insect’s wings, has a characteristic frequency called the “flight tone”; when produced by a female, it signals her presence to nearby males, thereby attracting potential mates.…

Aging brains lose their connections

Healthy aging is characterized by a gradual decline in cognitive function. Mental processes such as attention, memory and the ability to process information are at their peak when people are in their 30s and 40s, but as we get older, we find it increasingly difficult to focus on relevant information and to recall the names…