Kent Cochrane

Kent Cochrane (August 5, 1951 – March 27, 2014 ), also known as Patient K.C., was a widely studied Canadian memory disorder patient who has been used as a case study in over 20 neuropsychology papers over the span of 25 years.

Kent Cochrane was born on August 5, 1951, as the oldest of five children.

They grew up in the suburbs of Toronto, Ontario.

After attending a community college to study business administration, he obtained a quality control job at a manufacturing plant, which he held until the time of his motorcycle accident.

In 1981, Cochrane was involved in a motorcycle accident that left him with severe anterograde amnesia, as well as temporally graded retrograde amnesia.

Like other amnesic patients (patient HM, for example), Cochrane had his semantic memory intact, but lacked episodic memory with respect to his entire past.

As a case study, Cochrane has been linked to the breakdown of the single-memory single-locus hypothesis regarding amnesia, which states that an individual memory is localized to a single location in the brain.

In October 1981, Cochrane was involved in a single-vehicle accident on his way home from his job at a manufacturing plant when the motorcycle he was riding veered off of an exit ramp.

He suffered a traumatic brain injury.

Upon arrival at a hospital, Cochrane was experiencing clonic epileptic seizures and was unconscious.

Surgery to remove a left-side subdural hematoma was successful.

After a few days in the hospital, Cochrane was able to respond to simple commands.

After one week he was able to recognize his mother.

A follow-up CT scan revealed a chronic bilateral frontal subdural hematoma, enlarged ventricles and sulci, and left occipital lobe infarction.

Upon arrival at a rehabilitation facility, Cochrane was able to recognize friends and family, but still exhibited slower thinking ability, as well as partial right side paralysis and vision problems with his right eye.

Upon his discharge from the rehabilitation facility in July 1982, the full extent of Cochrane's neurological injuries was determined.

He had severe injury to his medial temporal lobes, along with almost complete bilateral hippocampal loss.

Ultimately, his neurological profile stabilized, as seen in CT scans he received once each decade following the accident.

As a result of his neurological damage, Cochrane suffered severe cognitive deficits that hindered his ability to form new episodic memories.

However, both his semantic memory and noetic consciousness remained unimpaired.

To illustrate this, research conducted on Cochrane has shown that he was able to recall factual information that he learned prior to his accident, such as his ability to know the difference between stalactites and stalagmites.

However, Cochrane was unable to remember emotional details of events from his past such as his brother's death and a dangerous fall he had at his home.

Cochrane also suffered from severe impairment of his autonoetic consciousness.

This meant that he was unable to envision himself in the future.

When asked what he would be doing later in a given day, month, or even a year, he was unable to respond with an answer.

Just as he could not remember being physically involved with events from his past, he was unable to imagine future events.

Ultimately, he lost any memory of his current actions once his thoughts were directed elsewhere.

Neuropathologically, Cochrane suffered from both anterograde amnesia and temporally graded retrograde amnesia.

Both forms of amnesia are characterized by damage to the medial temporal lobes, specifically within the hippocampal region.

The trauma caused by Cochrane's accident left him with severe anterograde amnesia that has made it impossible for him to remember both new personal experiences and semantic information.

As far as his temporally graded retrograde amnesia is concerned, he was considered an anomaly; in other words, his ability to recall events prior to the accident was dependent on when those events occurred.

Although he could not remember personally experienced events, his semantic knowledge prior to his accident remained intact.

For example, his recollection of factual information in math, history, and science, was unaffected.

Cochrane died on March 27, 2014, at the age of 62.

The exact cause of death is unknown, but his sister, Karen Casswell, said it is believed he had a heart attack or stroke.

He died in his room at an assisted living facility where he lived and the family opted not to authorize an autopsy.

Studies on Cochrane have provided researchers with information on various topics in neuroscience.

Implications of Cochrane's neuropathology have shown that damage to specific regions of the brain is associated with different forms of memory loss.

As a result of damage to Cochrane's medial temporal lobe, specifically his hippocampus, research suggests that this area functions in processing episodic memory.

However, damage to this area has left his semantic memory fully intact.