Over-Arousal: The Start of a Dangerous Cascade

Dogs often begin walks with heightened excitement. This state of arousal is driven by hormonal changes, including increased levels of adrenaline and corticosterone. While some excitement is normal, excessive arousal at the start of a walk can predispose dogs to reactive behavior. Encountering a trigger, such as another dog, a loud noise, or an unfamiliar object, can escalate their arousal levels further, leading to aggressive responses or fear reactions.

This escalation can result in the formation of maladaptive memories. When a dog is in an over-aroused state, their brain’s ability to process and store experiences shifts. Elevated corticosterone levels influence the amygdala, a brain region responsible for emotional processing, making the dog more likely to form strong, negative associations with the trigger (McEwen, 2007). These associations can persist and lead to long-term behavioral problems, including leash reactivity, fear aggression, or generalized anxiety.

The Role of Hormones in Memory Formation

When a dog experiences a stressful or threatening situation during a walk, their body’s fight-or-flight response is activated. This response releases adrenaline and corticosterone, hormones that prepare the body to react. While these hormones are essential for survival, they also play a significant role in memory formation and retrieval.

The hippocampus, which governs memory encoding and retrieval, works closely with the amygdala during stressful events. Adrenaline heightens attention and increases the likelihood of forming memories, particularly those associated with threats. However, when stress levels are too high, the hippocampus’s function can become impaired, leading to fragmented or distorted memories (Sapolsky, 2004). These maladaptive memories can resurface during future walks, causing the dog to react strongly to similar triggers, even in non-threatening situations.

Arousal-Related Neurochemicals and Their Role in Learning and Memory in Dogs

1. Dopamine

   • Dopamine is critical for reward-based learning and motivation. It is released during pleasurable activities or when a dog anticipates a reward (Schultz, 1998). High dopamine levels enhance the dog's drive to engage in tasks, making it a cornerstone of positive reinforcement training.

2. Norepinephrine

   • This neurotransmitter is involved in attention and arousal. Moderate norepinephrine levels improve focus and learning, while excessive amounts contribute to hypervigilance and stress responses (Sara, 2009).

3. Serotonin

   • Serotonin regulates mood and emotional stability. Balanced serotonin levels support calm and focus, which are conducive to learning. A deficiency in serotonin has been linked to increased anxiety and aggression, which can impair learning (Amat et al., 2013).

4. Endorphins

   • Endorphins are released during physical activity or pleasurable experiences, promoting feelings of well-being and reducing stress. These effects create an emotional state that facilitates learning (Koob & Volkow, 2010).

5. Adrenaline (Epinephrine)

   • Adrenaline, part of the fight-or-flight response, enhances memory encoding for emotionally salient events. However, excessive adrenaline can impair cognitive processing, leading to difficulty learning in high-stress environments (Cahill & McGaugh, 1998).

Stress-Arousal Curves and Learning

It turns out that there is just the right amount of arousal needed for optimal learning conditions. A dog that is not aroused at all laying in his bed won’t learn a new task. Similarly a dog that is over aroused can’t sit still long enough to even listen to you and therefore won’t learn either. However, a hungry dog looking for that high value reward is sufficiently aroused to perform the task in anticipation of the food reward.

The relationship between stress/arousal and learning follows the Yerkes-Dodson Law, which describes an inverted U-shaped curve:

• Low Arousal: Insufficient motivation, leading to disengagement and poor learning.

• Optimal Arousal: Enhances attention, memory, and task performance. This is the "sweet spot" for effective training.

• High Arousal: Impairs cognitive function, reduces memory retention, and may trigger reactive or maladaptive behaviors.

PTSD in Dogs: A Neuroscientific Parallel

Dogs are not immune to the effects of traumatic experiences. Over-arousal and repeated exposure to stressors can lead to behaviors analogous to post-traumatic stress disorder (PTSD) in humans. In both species, heightened activity in the amygdala and reduced control from the prefrontal cortex create a feedback loop of heightened reactivity and stress (Yehuda et al., 2015). For dogs, this may manifest as hypervigilance, avoidance behaviors, or aggressive outbursts during walks.

By teaching loose leash walking, owners can help their dogs remain calm, reducing the likelihood of over-arousal and the associated risks of maladaptive memory formation.

The Benefits of Loose Leash Walking

1. Promotes Calmness: Teaching LLW encourages a calm and controlled start to the walk, reducing the initial adrenaline surge. This sets the tone for a more relaxed experience.

2. Improves Focus: LLW training emphasizes engagement with the handler. A focused dog is less likely to react to triggers and can better navigate challenging environments.

3. Prevents Escalation: A dog walking calmly on a loose leash is less likely to encounter situations where over-arousal leads to reactive behavior. This reduces the chances of forming negative associations with triggers.

4. Supports Long-Term Emotional Health: By minimizing stress and arousal during walks, LLW helps protect against the chronic stress that can contribute to anxiety and other behavioral disorders.

Neuroscience-Informed Training Strategies

1. Start with Low-Arousal Activities: Before heading out, engage your dog in calming activities such as sniffing games or light obedience exercises. This helps lower baseline arousal levels.

2. Reward Calm Behavior: Use positive reinforcement to reward your dog for walking calmly beside you. High-value treats or praise can help reinforce the desired behavior.

3. Use Trigger Desensitization: Gradually expose your dog to triggers in a controlled manner, ensuring they remain below their arousal threshold. Pairing triggers with positive outcomes can help reshape their emotional response.

4. Practice Controlled Walks: Begin training in a quiet, low-distraction environment before progressing to more challenging settings. Consistency and patience are key.

The Role of Owners in Shaping Positive Experiences

Owners play a crucial role in managing their dog’s emotional state during walks. Understanding the impact of over-arousal on memory and behavior can empower owners to approach training with empathy and scientific insight. By prioritizing loose leash walking, owners can foster a safer and more enjoyable experience for both themselves and their dogs.

Conclusion

Loose leash walking is more than a training exercise; it’s a preventive measure that safeguards your dog’s emotional and psychological health. By keeping arousal levels in check and minimizing exposure to stressors, LLW helps prevent the formation of maladaptive memories and reduces the risk of long-term behavioral issues. With the guidance of neuroscience, we can better understand the importance of calm, controlled walks and provide our dogs with the tools they need to thrive in a complex world.

PHJ Dog Training is led by Pepe J. Hernandez, Ph.D., a behavioral neuroscientist and dog trainer. One of his goals is to educate those who own or work with dogs about the function of the brain in behavior in working towards practical easy to use training strategies to change, introduce, or eliminate certain behaviors in their dogs. Log onto www.PJHdogtraining.com to see training services offered and how to sign up for private or group training classes.

References

• Amat, M., Manteca, X., De La Torre, J. L. R., & Fatjó, J. (2013). "Aggression in Dogs: Toward a Positive Emotional Management of Aggression." Journal of Veterinary Behavior: Clinical Applications and Research, 8(5), 360–374. https://doi.org/10.1016/j.jveb.2012.09.044

• Cahill, L., & McGaugh, J. L. (1998). "Mechanisms of Emotional Arousal and Lasting Declarative Memory." Trends in Neurosciences, 21(7), 294–299. https://doi.org/10.1016/S0166-2236(97)01164-7

• Koob, G. F., & Volkow, N. D. (2010). "Neurocircuitry of Addiction." Neuropsychopharmacology, 35(1), 217–238. https://doi.org/10.1038/npp.2009.110

• McEwen, B. S. (2007). "Physiology and Neurobiology of Stress and Adaptation: Central Role of the Brain." Physiological Reviews, 87(3), 873–904. https://doi.org/10.1152/physrev.00041.2006

• Sapolsky, R. M. (2004). Why Zebras Don’t Get Ulcers: The Acclaimed Guide to Stress, Stress-Related Diseases, and Coping (3rd ed.). Henry Holt and Company.

• Sara, S. J. (2009). "The Locus Coeruleus and Noradrenergic Modulation of Cognition." Nature Reviews Neuroscience, 10(3), 211–223. https://doi.org/10.1038/nrn2573

• Schultz, W. (1998). "Predictive Reward Signal of Dopamine Neurons." Journal of Neurophysiology, 80(1), 1–27. https://doi.org/10.1152/jn.1998.80.1.1