How Do Dogs Develop Fear Memories?

A fearful dog on owner's lap

 

How do dogs develop fear memories? This may be something you may be wondering about, especially if you own a fearful dog.

Your dog might not remember exactly what kind of treat you fed him yesterday or what shirt you were wearing. But ask him where he was when he heard a loud noise and startled, and he’ll recall the exact location.

When it comes to recollecting stressful and scary events, dogs seem to have the uncanny ability to remember quite well.

Owners of dogs suffering from noise phobias know this too well. All it takes is a loud noise for their dog to activate all sorts of avoidance behaviors when they encounter the same area again.

As much as this sounds like a bad thing, the fact that fear sinks in deep, is survival instinct working at best.

So How Do Dogs Develop Fear Memories?

Dogs form fear memories courtesy of their a process known as fear conditioning. This is something that is deeply rooted in their brain’s survival mechanisms.

When a dog experiences something frightening, whether it’s a loud noise, a sudden movement, or a negative interaction, the amygdala, the brain’s fear center, rapidly processes the event.

If the experience is intense or repeated, the hippocampus stores contextual details, creating a lasting memory of the fearful stimulus.

The Power of Stress

During times of stress, the amygdala, the brain’s fear center, immediately assesses the threat and triggers the fight-or-flight response. This happens without conscious thought.

Soon, a chain of physiological events take place as the dog’s body is bombarded with the release of stress hormones into the blood stream.

These hormones and all their associated physiological changes are there for a good reason: to up the dog’s chances for survival.

The dog’s heart rate and breathing increase. His senses are amplified. The ears are ready to capture the slightest sounds and the pupils dilate so Rover can see with more clarity.

At the same time, muscles receive increased blood flow so that the dog can sprint into action.

The dog’s blood pressure increases and a surge in blood sugar released from the kidneys provides a boost of energy.

The dog’s appetite is suppressed as blood flows away from the digestive tract to the muscles for action. Indeed, try dangling a slice of baloney in the face of a terrified dog.

Several changes also take place at a mental level. Dogs who are stressed and frightened, have a hard time concentrating, and their impulse control and bite threshold may lower. When it comes to memory though, the ability to recall the event seems to sharpen.

Scared dog with ears back

Everlasting Bad Memories

So how do dogs form fear memories? Negative events are known to leave an impact on those who are involved..

Ask anybody what they were doing on September 11th 2001, and most people will have a clear recollection. “I was stacking supplies at the store.” “I was eating lunch with a friend.” Or “I was playing soccer when my sister called and gave me the news.”

Then ask anybody what they were doing a week ago, and they’ll likely give you a blank stare.

It’s natural for people and animals to remember bad episodes, especially when they are situations that had a strong emotional impact or that could have hurt somebody significantly.

It makes sense for stress hormones to help recollect memories of events that take place when we’re undergoing stress,  explains Roger Abrantes, PhD in Evolutionary Biology and Ethology and director at the Ethology Institute Cambridge.

“We cannot know what dogs “perceive,” but we do know that dogs have excellent memories and the same brain architecture and functions as humans do, so when we see behaviors consistent with true panic, even if the stimuli are not present, we need to consider that memory of these stimuli… could be what is distressing the dog.”~ Karen Overall.

Fear Through Generations

Interestingly, fearful responses to certain stimuli may be even passed from a generation to another.

In a study published in the Journal of Nature Neuroscience, rats were given an electric shock each time they were presented with acetophenone, a compound that gives off a scent resembling cherry blossoms.

Shock after shock, the rats soon becomes sensitized to the the scent resembling cherry blossoms and they would show a fearful response.

After being bred, these rats gave birth to offspring who,without any prior conditioning (learning,) showed fearful responses to the scent despite never having witnessed it before.

 This demonstrates that it is possible to pass down fear of a smell even in several generations. This makes evolutionary sense if you think about it, since teaching future generations to recognize the scent of dangers, can up the chances for survival.

It’s all quite fascinating, and surely more studies are needed on this to understand the exact dynamics, (hopefully without the need for shock!)

Did you know? When an intensely unpleasant or aversive event leads to a dog developing a fearful lasting memory, it’s known as “one-event learning,” explain  Gary M. Landsberg, Wayne L. Hunthausen and Lowell J. Ackerman in the book “Behavior Problems of the Dog and Cat.

References

  • Parental olfactory experience influences behavior and neural structure in subsequent generations, by Brian G Dias & Kerry J Ressler, Nature Neuroscience17,89–96
  • “How epigenetic memory is passed through generations: Sperm and eggs transmit memory of gene repression to embryos.”University of California – Santa Cruz. ScienceDaily. ScienceDaily, 18 September 2014.
  • Ethology Institute of Cambridge, Bonding and Stress, by Roger Abrantes, retrieved from the web on July 29th, 2016
  • Manual of Clinical Behavioral Medicine for Dogs and Cats, By Karen Overall, Mosby; 1 Pap/DVD edition (July 9, 2013)
  • Behavior Problems of the Dog and Cat3: Behavior Problems of the Dog and Cat, By Gary M. Landsberg, Wayne L. Hunthausen, Lowell J. Ackerman, Saunders Ltd.; 3 edition (December 28, 2012)