fMRI

Neurophilosophy

Category archives for fMRI

Brain mechanisms of Freudian repression

More than 100 years ago, Sigmund Freud, the father of psychoanalysis, proposed a mechanism called repression, whereby desires and impulses are actively pushed into the unconscious mind. For Freud, repression was a defence mechanism – the repressed memories are often traumatic in nature, but, although hidden, they continue to exert an effect on behaviour. Many…

Reading the contents of working memory

Working memory refers to the process by which small amounts of information relevant to the task at hand are retained for short periods of time. For example, before cellular phones became so ubiquitous, calling someone usually involved first finding the number and then remembering it for a just few seconds by repeating it to oneself…

Tracing memories

During the first half of the twentieth century, the American psychologist Karl Lashley conducted a series of experiments in an attempt to identify the part of the brain in which memories are stored. In his now famous investigations, Lashley trained rats to find their way through a maze, then tried to erase the memory trace…

Visual images reconstructed from brain activity

Recent advances in functional neuroimaging have enabled researchers to predict perceptual experiences with a high degree of accuracy. For example, it is possible to determine whether a subject is looking at a face or some other category of visual stimulus, such as a house. This is possible because we know that specific regions of the…

Neurobiology of a hallucination

Hallucinations are often associated with psychiatric conditions such as schizophrenia or with LSD and related drugs. Hearing voices is a characteristic symptom which is reported by about 70% of schizophrenic patients, as well as by some 15% of patients with mood disorders such as depression; and those under the influence of LSD often experience extreme…

MRI: What is it good for?

We are being constantly bombarded with news stories containing pretty pictures of the brain, with headings such as “Brain’s adventure centre located“. Journalists now seem to refer routinely to functional magnetic resonance imaging (fMRI) as “mind reading”, and exaggerated claims about its powers abound, as do misleading, irresponsible and downright ridiculous stories about the technology.…