It's a sure bet that the next time you hold a meeting, make a sales presentation, or attend a networking event, you will send non-verbal communication signals to other people. It happens all the time, and most of us don't even notice it.

Truth is body language matters--especially positive body language--to help put out a good vibe and raise your likability. You want to master it because it's what people see first before you even speak a word.

But then there's the toxic side of body language--what kills normal verbal discourse and drastically diminishes your ability to persuade and be effective.

In an effort to better understand the business of body language for this piece, I reached out to a bona fide expert in the field, Donna Van Natten, known as the "Body Language Dr." She is the author of a provocative book, Image Scrimmage --a research-packed, how-to manual on the dos and don'ts of nonverbal communication.

4 Toxic Body Language Habits

Van Natten wasted no time giving me a specific set of non-verbal signals we may be transmitting, which she considers "toxic." Who's guilty? (I can raise my hand to at least two of these in the past)

1. Space invaders.

According to Van Natten, no one likes to feel crowded or intimidated by another person's body looking in. While the rules of proxemics aren't posted, we know when it's OK for someone to get close, closer, or to back off. We need to respect the rules based on the nature of the relationship. This applies to work as well.

2. Fingerpointing.

People quickly perceive it as aggressive and it often feels like a stab. While fingerpointers opt to point at others to 'get their point across' and give direction, it comes across too strong. The hands are an extension of one's thoughts and pointing feels like stabbing. "This is core to us because we learned this in childhood when we were singled out by an authority figure's pointed finger right at us," explains Van Natten.

3. Eye rolling.

People like to think they are clever when rolling their eyes and no one actually notices when they do it. But, truth be told, the receiver is constantly looking at the eyes for nonverbal communication. Other than having something in the eye, Van Natten explained that there is no need to roll the eyes; therefore, it's important that we understand the negative implications of frustration or disbelief when we see someone rolling their eyes.

4. Smell.

Van Natten says that our olfactory bulb is literally right next to our amygdala in our brains, making us hypersensitive to smells. And "smells evoke an emotion in us," she adds. We've probably all sat near a coworker or classmate who smells foul or has horrible breath and we worked hard to avoid that person. Reputations are even ruined when someone omits an odor which we find offensive or toxic. For example, people will literally scrunch their noses or step back to avoid the pungent odors when they are bad. "People need to be keenly aware of this regarding their own bodies," states Van Natten.